Non MS Exchange server settings/setup?

Have a bit of a conundrum, our domain is registered with MS and we will shift to 365 eventually.
We are still using an on premises exchange server and I could always use emclient before.

It appears once I put my email in that it doesn’t want to allow me to manually configure my settings, it defaults to trying to have me login on https://login.microsoftonline.com/.

Anyway to trigger or get back the old manual option, so I can enter the settings in manually?

Our Outlook 2013 works fine, 365 users have to use a reg tweak for now.