I'd do this a little differently. I'd use a full sheet manual brailler, and make the grid with the Braille alphabet (minus Z) written with one letter in the center of each square.
The center square is either "free space" or it can contain a prompt, so it's a minor matter.
Then, just print a list of twenty-five random prompts in Braille-- https://www.random.org/lists/ will generate a list pasted into the text box. If you need help with that, PM me and I'll set this up for each month's bingo theme.
Each item goes to a letter/number, and the card can be reused, since the randomized list is a separate page.
Tactile bingo card
The center square is either "free space" or it can contain a prompt, so it's a minor matter.
Then, just print a list of twenty-five random prompts in Braille-- https://www.random.org/lists/ will generate a list pasted into the text box. If you need help with that, PM me and I'll set this up for each month's bingo theme.
Each item goes to a letter/number, and the card can be reused, since the randomized list is a separate page.