@dcm91 I really don't know where the gamelist.xml will be placed because I have no idea how this image is set up. These files can go in 2 places, within each system ROM folder or in /home/pi/.emulationstation/gamelists/systemname. Or at least that's where they go in the standard image. They could be absolutely anywhere on a custom image. You'll just have to try it and see.
Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first