New User - unable to add OWA accounts

Here in the UK our provider (BT) has converted our POP accounts to OWA (Outlook Web Access) accounts. It appears we can no longer use email clients such as traditional Outlook but are forced to use “New Outlook” which is significantly inferior. eM Client seems to offer much better facilities (especially including offline storage) but I am unable to add these accounts; 2 are @btconnect.com and 3 are @(ourdomain).co.uk.
Is there an answer to this please?

Unfortunately BT decided that BT Connect customers can no longer use email applications to access their mail.

You will need to follow their instructions and use webmail instead.

See: The security of btconnect.com email is being improved | BT Business

Yes - thanks Gary. Been there… That’s our problem.
Can I therefore assume that eM Client won’t work for us?