For the patch to the main, use version 2.2 of Simlock Patch Generator as this is the one that patches CID53 versions of main.

Also check this tutorial below as it was a big help to me, unlock works on CID53 K770i, took me 3 days to work out how to do mine, however once learnt took me 30minutes to sort the wifes out which is same phone!

In the tutorials when it mentions making the .rest file, don't bother as in this section you can use the normal main file when originally flashed the phone to debrand!

Any/ALL CID Patching Tutorial/Guide DB2020 | SE Flashing