Sorry, I can't help you with Godot. The font sprite sheet can be used to create a font file. There are several tools and guides you can find online for this purpose. And glad to know you liked the assets.
I've found a way to use it on Godot after a little while, not so easy but it worked as expected!Btw, I've just released a game using this pack if you want to check it out (here).
Thanks for your support and the assets =D
That's great!