You can renew the https certificate during runtime using the following CLI command ip https certgen

Example:

(Hirschmann Railswitch) #show ip https

HTTPS Mode: ................................... Enabled
Secure Port: .................................. 443
HTTPS certificate fingerprint SHA-1: .......... 2C:25:C4:13:B9:5B:CA:48:5B:E7:D7:31:A3:4B:4F:38:B4:B9:42:E4
HTTPS certificate fingerprint SHA-256: ........ B7:35:24:BA:06:F0:03:35:60:5F:D5:75:CA:B7:5E:38:01:03:08:65:11:42:87:21:00:4D:A3:49:DB:B9:BF:FC

(Hirschmann Railswitch) #ip https certgen
The generation of the certificate might take up to several minutes.
The Command Line Interface will be blocked until the certificate is generated.

Certificate successfully generated.

(Hirschmann Railswitch) #show ip https

HTTPS Mode: ................................... Enabled
Secure Port: .................................. 443
HTTPS certificate fingerprint SHA-1: .......... 8A:94:44:45:7B:5F:E4:8B:DC:66:0A:E8:B7:E6:E2:7F:AF:7A:15:7B
HTTPS certificate fingerprint SHA-256: ........ 0B:87:AE:98:06:1E:7B:36:76:88:68:DE:59:9B:78:9A:6B:F4:6F:78:8B:56:2F:EF:4D:64:DA:A7:AF:21:FF:57

(Hirschmann Railswitch) #

After that you need to restart the webserver to take effect.

(Hirschmann Railswitch) #no ip https server

(Hirschmann Railswitch) #ip https server