Is there an app for your own custom keyboard to write in your own language?

I have a language that uses a different alphabet that I made, but without having to use a completely different font maker and such, is there a way i could still type with it?

The best I can think of is just using a font maker or doing it my hand, if it's an alphabet you made then it will be very difficult to get a 'keyboard' without it as a font. I recommend Calligraphr, its easy to use and free for simple sets of letters. I don't really know how you would otherwise be able to have your custom alphabet.

Ok thank u! /gen