Is the OAuth authentication exclusive to paid editions? I cannot find the OAuth in Authentication.
p.s. My installation is from Turnkey Linux.

Same here with me, i am also not able to find the oauth and also not able to configure

15 days later

We discovered the same after installing the Turnkey Linux for Faveo Helpdesk in our Proxmox environment.
[Edit: Installing SERVICEDESK revealed the OAuth setting.]
We are trying to install Faveo Servicedesk in order to compare the features. We are under the impression that Serivcedesk is aimed at "enterprise" which would have more of a need for OAuth, whereas smaller organizations can use a traditional IMAP/POP setup.

Did you have any more luck finding the OAuth settings?

2 months later