How to update ManicTime Server certificate on Windows
To change the certificate from command prompt:
Run cmd as admin, then write
netsh http add sslcert appid="{4780cfe6-2b27-4089-901f-e7762c8ea68f}" ipport=0.0.0.0:<manictime server port number> certhash=<certificate thumbprint>
There are two important things, port number and certificate hash.
Port is whatever you are using.
How to get the hash:

Once you run this, ManicTime Server will use a different certificate.