Clear vfs cache so large file can be uploaded

I am copying a large file around 8GB into a mounted google drive folder.

The vfs cache is at 10GB, but I want rclone to upload the file now and right now.

What is a command I can run to do that?

Or could it be uploading already just not showing up on google drive web?

Please use the help and support topic as without any details of what you are running, it is hard to help.