SSL Certifificate with internal step-ca for EMS Server 7.4.5

Hello everybody,

we are using the FortiClient EMS Server Appliance and want to use our private step-ca as the ACME server for the EMS certificate, including automatic renewal.

We do not want to expose EMS to the internet just to use Let’s Encrypt, and we would also like to avoid manual certificate replacement.

Has anyone done this with the EMS Appliance, and if yes, how did you get EMS to trust the private ACME CA?

Thanks in advance