This is the customizer for the A-maze-ing gift card box, that allows you to personalize the message on the top.
To use, press the 'open in customizer', and type your message in the three fields. If you have a really long message use the first two fields and leave the last one blank. Once printed, visit the the base thing, and print the rest of the pieces (follow instructions there).
If you do print a maze gift card holder with a creative message, please share in a comment here.
Special thanks to Riham for her stl to openscad converter, and to wifibum for pointing it out to me.