Getting an error when trying to connect zoho mail to Make

Getting an error when trying to connect zoho mail to Make

Hi,
I'm trying to send an email via Make Integration.
I configured the Server application and set the connection in Make Scenario.
When I hit the save button I get an error from Zoho:
Invalid Redirect Uri
Redirect URI passed does not match with the one configured

What should be in the Redirect URI?
I used https://www.mysite.com/callback
What should be the content of the page callback?

Sam