Unable to create the point cloud neither with help of API nor from the connect Bentley portal

Good Morning,
hello this is Akshay here i was exploring the possibilities of the Bentley itwin services i wanted to append the point cloud on the model, i have been trying the "create point cloud API "as suggested in the tutorials and also the create workspace for point cloud ,none of these work it says not enough permissions i mean all the scopes are set accordingly i am the only user hence the administrator yet I am unable to set up point cloud for my model kindly guide me the work flow for this as well as if there is video tutorial that I can explore then it would be awesome  as i am on trial period of 90 days its not letting me download the tools needed for optimization and upload of point cloud which can be used in connect Bentley services. the error code i get is 403 kindly help me through this.