msf > load msgrpc
[*] MSGRPC Service: 127.0.0.1:55552
[*] MSGRPC Username: msf
[*] MSGRPC Password: aKCU4AgT
[*] Successfully loaded plugin: msgrpc
msf >
Now start msfrpcd with -P
Reference https://help.rapid7.com/metasploit/Content/framework/msf-rpc-service.html for more info.