Synology DS718+ - How to mount Google Drive

Hi - I am wondering how I can mount Dropbox or Google Drive to Synology Server to “expand” my storage for Plex.

My current DS718+ is beginning to run low on space I have 2.2 TB of 2.5 TB. I read in some areas that there is a way to mount a Google Drive or Dropbox onto your server for Plex, however unsure how to do this and would like some help.

Does anyone have any ideas on how to go about doing this?

I know there is a way to “link” a cloud drive on Plex but isn’t this only for Plex Cloud which will be discontinued?

I appreciate your help and guidance.