Stamp handle and die

Emboss the provided blank die with your design or text, then glue it to the stamp handle.
1.8 mm high text worked for me.

If you create your own die, remember to mirror it before printing.
The ones provided here are already mirrored.

Use the "ironing" option in your slicer to optimize the finish of the top most layer of your text.
Channel at the bottom of the handle helps with excess glue or epoxy...

Ideally:
Print the die in TPU to stamp paper.
Print the die in PLA to stamp leather, fabric, or unfired clay.