I can’t embed it here, but I made a Vimeo video tutorial showing how to use Photopea to make lettering quickly and easily for use in Miro.

Using Miro in one browser tab and Photopea in another, it’s fairly trivial to make text using fonts not included in Miro. Photopea has limitless fonts, and you can just cut and paste your text layer back into Miro. Easy!