3.7.94 is very old, but IIRC make sure interface scale is 100 and the language is not Chinese, Japanese, or Korean. Then as long as the font size is Medium or Large, it should be possible to choose Bitmap.
You can change it in the settings file, though Spine may do the same checks as the UI does and disallow it. The settings file for 3.7 is at:
Windows: <user home folder>\Spine\prefs.json
Mac: <user home folder>/Library/Application Support/Spine/prefs.json
Linux: <user home folder>/.spine/prefs.json
You should see font (set to "Bitmap"), fontSize (set to 13 or 15), uiScale (set to 1), and language (set to English, for example). You could also copy the prefs.json from the computer where fonts are working like you want.