Create self-signed certificates with openssl for MIkrotik SSTP VPN server

Hi all. I want to create self-signed certificates with openssl for the use of SSTP VPN server on Mikrotik. Afterwards I want to import them on 2 devices, as one is the backup device. Because RouterOS doesn’t allow to export/import certificates on another Mikrotik device, actualy you can export/import but the certificates won’t work, no “K” (private key) letter will not be active. I found a howto in order to generate the certificates but some steps are missing. Could someone point me please to a working solution? I’m sure somebody already did it. Thank you in advance.

Just generate self signed cert on the router itself
All the info is in the manual
https://help.mikrotik.com/docs/spaces/ROS/pages/2555969/Certificates

absolutely FALSE and WRONG

At most, as it SHOULD BE, it does not allow you to duplicate the Certificate Authority,
but is still possible export and import public and private certificates.