text – part of the sprite or dynamically generated

I am trying to reproduce the same stamping tool as the one we found in the video game "Papers, Please".

In my case I want my users to be able to modify the text they are going to stamp. I will use a similar blocky font.

As you probably noticed in this sprite, the top of the letters is clearer in order to give an effect of depth.

How should I proceed to copy the same effect? The only solution that came to mind was to create sprites for each needed letter and then include them dynamically over my sprite but there has to be a more efficient way. I suspect the author directly drew them in the sprite but I’m not sure.

red stamping tool from the video game "Papers, Please"