If you want to move Seq's logs off your server's C drive, please refer to the software's help page on that topic!
Seq's extent files will consume "infinite" amounts of disk space unless a retention policy is configured to delete the oldest files after a set period of time.
By default these files are saved on the C drive, where a lack of disk space can cause application crashes.
(What is an extent file? They provide longer-term storage for the older messages that don't fit into the available RAM capacity of the Seq service.)
A retention policy is a very good idea, regardless of where these files are saved.
Navigate to the Settings of the Seq service, and from there, choose Retention from the left-side menu.
Bentley recommends designating adequate disk space to keep the extent files for the longest practical time, to support troubleshooting of older events where possible.