how to create a new file instance via Bentley Web Services Gateway Web API

Question

I'm new of Web API and I'm trying to upload a new file. 
 I think I need to create a new file instance by using this url POST v2.5/Repositories/{repositoryId}/{schema}/{class} 
 but I got this error below. 
 
 { 
 "errorId" : "ClassNotFound" , 
 "errorMessage" : "Class 'FileAccess' was not found in schema 'PW_WSG'." , 
 "errorDescription" : null 
 } 
 
 so I'm wondering what schema and class I need to use 
 
 we have the list of schema below at the moment.

{ 
 "instances" : [ 
 { 
 "instanceId" : "N~3APW_WSG_Dynamic.01.02" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "PW_WSG_Dynamic" , 
 "DisplayLabel" : "ProjectWise Web Services Gateway Dynamic Schema" , 
 "NameSpacePrefix" : "pwdynamic" , 
 "Description" : "Schema used for ProjectWise plugin for Bentley Web Services Gateway." , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 2 
 }, 
 "eTag" : "\"tj2gn0sTjQ8ky/J2uTs3sPTz+K4=\"" 
 }, 
 { 
 "instanceId" : "N~3APW_WSG.02.05" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "PW_WSG" , 
 "DisplayLabel" : "ProjectWise Web Services Gateway Schema" , 
 "NameSpacePrefix" : "pwwsg" , 
 "Description" : "Schema used for ProjectWise plugin for Bentley Web Services Gateway." , 
 "VersionMajor" : 2 , 
 "VersionMinor" : 5 
 }, 
 "eTag" : "\"5cSW9uCHjdAVOst3X4+DZaaAeQw=\"" 
 }, 
 { 
 "instanceId" : "N~3ABentley_Standard_CustomAttributes.01.13" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "Bentley_Standard_CustomAttributes" , 
 "DisplayLabel" : "Bentley Standard Custom Attributes" , 
 "NameSpacePrefix" : "bsca" , 
 "Description" : "Bentley Standard Custom Attributes" , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 13 
 }, 
 "eTag" : "\"zhfZga8D7RZf0mbqUkJnuzaVc2c=\"" 
 }, 
 { 
 "instanceId" : "N~3AEditorCustomAttributes.01.03" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "EditorCustomAttributes" , 
 "DisplayLabel" : "EditorCustomAttributes" , 
 "NameSpacePrefix" : "beca" , 
 "Description" : null , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 3 
 }, 
 "eTag" : "\"TGTDnkpIZmr16XjPo566uXb29WY=\"" 
 }, 
 { 
 "instanceId" : "N~3ADataSourceSpecification.02.02" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "DataSourceSpecification" , 
 "DisplayLabel" : "DataSourceSpecification" , 
 "NameSpacePrefix" : "DSS" , 
 "Description" : null , 
 "VersionMajor" : 2 , 
 "VersionMinor" : 2 
 }, 
 "eTag" : "\"m/wCVUt6Gfc+UNBd161KytK+4iQ=\"" 
 }, 
 { 
 "instanceId" : "N~3AECDbMap.01.00" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "ECDbMap" , 
 "DisplayLabel" : "EC DB Mapping" , 
 "NameSpacePrefix" : "ecdbmap" , 
 "Description" : "Custom attributes that customize the ECSchema to database mapping." , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 0 
 }, 
 "eTag" : "\"UzBrRxyx8JrH0lvef0oNyknb6Ts=\"" 
 }, 
 { 
 "instanceId" : "N~3AForms_EC_Mapping.02.00" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "Forms_EC_Mapping" , 
 "DisplayLabel" : "Forms EC Mapping" , 
 "NameSpacePrefix" : "Forms" , 
 "Description" : "Forms EC Mapping" , 
 "VersionMajor" : 2 , 
 "VersionMinor" : 0 
 }, 
 "eTag" : "\"Urj8pffkfqaVQt2rpXS4kbMIsHY=\"" 
 }, 
 { 
 "instanceId" : "N~3AMetaSchema.02.04" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "MetaSchema" , 
 "DisplayLabel" : "MetaSchema" , 
 "NameSpacePrefix" : "ms" , 
 "Description" : null , 
 "VersionMajor" : 2 , 
 "VersionMinor" : 4 
 }, 
 "eTag" : "\"ugr7KCzVwyutaMnj35ww2rwj0WI=\"" 
 }, 
 { 
 "instanceId" : "N~3ABentley_Standard_Classes.01.01" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "Bentley_Standard_Classes" , 
 "DisplayLabel" : "Bentley Standard Classes" , 
 "NameSpacePrefix" : "bsm" , 
 "Description" : "Bentley Standard Classes" , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 1 
 }, 
 "eTag" : "\"Vqd+w0qJn0uF5t0NcaMCxm9sHKw=\"" 
 }, 
 { 
 "instanceId" : "N~3ANavigation.01.01" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "Navigation" , 
 "DisplayLabel" : "Navigation" , 
 "NameSpacePrefix" : "rest_nav" , 
 "Description" : null , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 1 
 }, 
 "eTag" : "\"XwDZVzUcN132fIyhUQ6FAaPjEUU=\"" 
 }, 
 { 
 "instanceId" : "N~3AJobs.01.00" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "Jobs" , 
 "DisplayLabel" : "Jobs" , 
 "NameSpacePrefix" : "j" , 
 "Description" : "Schema defining asyncronous job." , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 0 
 }, 
 "eTag" : "\"JZllIlThzdIYOHCKH6kaM0XhUBw=\"" 
 }, 
 { 
 "instanceId" : "N~3APresentationRuleSet.01.00" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "PresentationRuleSet" , 
 "DisplayLabel" : "PresentationRuleSet" , 
 "NameSpacePrefix" : "PRS" , 
 "Description" : "Presentation Rule Set Locater Schema" , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 0 
 }, 
 "eTag" : "\"8emiF0qMBxoL5YTxsuWAE2eJwao=\"" 
 }, 
 { 
 "instanceId" : "N~3AFileAccess.01.00" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "FileAccess" , 
 "DisplayLabel" : "FileAccess" , 
 "NameSpacePrefix" : "rest_fa" , 
 "Description" : "Schema defining file access information." , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 0 
 }, 
 "eTag" : "\"WSMNRxygQUbK5d+tqpBNy4EHnp0=\"" 
 }, 
 { 
 "instanceId" : "N~3APolicies.01.01" , 
 "schemaName" : "MetaSchema" , 
 "className" : "ECSchemaDef" , 
 "properties" : { 
 "Name" : "Policies" , 
 "DisplayLabel" : "Policies" , 
 "NameSpacePrefix" : "rest_pol" , 
 "Description" : null , 
 "VersionMajor" : 1 , 
 "VersionMinor" : 1 
 }, 
 "eTag" : "\"TD71Mc1LZR6uAba553UJHMAWktw=\"" 
 } 
 ] 
 }