Replacing AAA batteries with a DC power adapter

My adaptation of a dummy battery 3D print model from thingiverse - https://www.thingiverse.com/thing:6467582 ; I'm replacing the six AAA batteries of my label printer with a DC socket for 9V. One bummer though: The printer only has volatile memory for storing settings, so once I disconnect and reconnect the power, it goes back to factory (language, font size etc.)...