Hello!
The product you have provided information about belongs to the carrier series. Please contact your local carrier or product sales agent to obtain the correct software.
The ONT is used together with the OLT at the central site. The version must match the model. If the version is incorrect, it cannot work.
Once you've gotten the firmware, perform the upgrade or downgrade under the supervision of professional personnel.
Otherwise, the fault cannot be rectified. Be careful when performing this operation.
Please contact your equipment supplier
Thank you!