I talked with support of mikrotik "email@example.com
" and he said that they are working in a new firmware to this module GPON. We'll have to wait by the new firmware of GPON....
There is a new firmware in development at the moment. When it's released then it will be possible to change various registration ID's and Passwords in the module. At the moment however it is not yet know when it's going to be released.
Also current batch modules will only be upgradable through OLT.