Dropbox Backup Failure ERPNext V13

Trying to get Dropbox backup working on V13, but it throws the following error during the setup

requests.exceptions.HTTPError: 400 Client Error: Bad Request for url: https://api.dropboxapi.com/oauth2/token

Looking at Dropbox forums there is similar error states after 2020 on the dropbox changes. Article below desribes it.

Anyone knows how to fix it? Or what file to modify in the ERPNext? The following snippet is from the above dropboxforum entry. So perhaps by replacing the https://api.dropboxapi.com/oauth2/token to he one recommended will fix the issue?

I seems found the reason .

My endpoint to do the second step was


when i replaced it to


all wtarted to work fine.

Have now updated to latest version of 13. The same error continues. Any ideas?

ERPNext: v13.49.5 (version-13)
Frappe Framework: v13.51.1 (version-13)