The cert-issuer failed while building docker image

The cert-issuer failed while building docker image:
Error: Config setting for -rpcport only applied on regtest network when in [regtest] section. Please help

You already posted in cert-issuer.
You need to take a look at your configuration, the error is quite explicit, it seems you can’t have rpcport set with regtest network. At least this is how I interpret the error, I have never faced it myself.