Not receiving confirmation email

We are not receiving the confirmation emails. A few notes to help you:

A provider has been set up: we arent’ receiving those emails either though

Settings page: the auto notification is on YES or first two settings, to send it and receive it

Any help would be appreciated, I can send any more info that you need!

I realize that my version of WP might be too recent but I also read somewhere that it works fine with the most current version in testing…?

https://wordpress.org/plugins/appointments/