Hello, first need to know the phone model and firmware version to make sure that it is on the support list.
If you've already tried to repair without results, please add logs.
Use your original IMEI to repair the phone.
Press the 'Patch Certificate' if you have a network problem after repairing.
Please note that it should not start from zero.
If the IMEI starts with 0, the device will identify it as not valid in any case. Replace code. And then make a patch.
We don't allow to change IMEI, our tool is only to restore the original one.