Hestia Global SMTP Relay Mailgun

Hello there,
i am getting an error while i am trying to add global smtp relay.
I created a Mailgun Account. Added every credential in the global smtp relay:
But i am getting following error.

Are you sure you setup their DNS records correctly?

I think so. Because mailgun shows everything as verified.

The sendin domain and the subdomain added on mailgun has to be the same?

I need here really help. If you have any suggestions pls share.