M-Files for Microsoft Teams configurations

Hi, 

I have set up M-files for Microsoft Teams with instructions found on https://catalog.m-files.com/shop/m-files-for-teams-and-sharepoint-online/

We have on-premise Mfiles vault.

Error I keep getting is “Sorry, we cant use the given web address. Please make sure the address is correct and try again.” The address is correct, copied from m-files web.

What am I missing here?