Let's look at the patch timeline for this device:
Connect via ADB or fastboot and run:
If your locked Nokia G21 runs a security patch from (or later), you cannot flash a dump file from January 2023 . Why? Because Unisoc processors (which power the TA-1418) use a rollback index stored in the Trusted Execution Environment (TEE).
Always verify the security patch date of the dump file before purchasing or flashing.