Custom Keyboard Layout MacOS

TL;DR Download the Akan layout bundle, unzip and continue at point 10. The above bundle replaces two hardly used letters on the US international keyboard:
option + ; = ɔ and option + shift + ; = Ɔ and
option + ' = ɛ and option + shift + ' = Ɛ

I wanted to write some text in Akan, but macOS doesn't provide any keyboard layouts with ɔ/Ɔ or ɛ/Ɛ. So I had to create a custom layout. Unfortunately the Akan MacOS X Keyboard from kasahorow.org didn't work. So I had to create one my self. Here are the steps with macOS 12.3 and Ukelele 3.5.5:

1. Install Ukelele
2. Open Ukelele
3. Change to Input Source you want to base your new keyboard layout on.
4. Close Empty Keyboard Window
5. File > New From Current Input Source
6. Right mouse click > Open Keyboard Layout (alternatively just double click)
7. (Optional) Righ click and change Keyboard Name and Keyboard Language and even the Keyboard Icon
8. Edit accordingly
9. File > Save...
10. Find your file in Finder and double click. If asked to choose a application to open, choose "Keyboard Installer". (Optional: If all fails, move the .bundle file into ~/Library/Keyboard Layouts folder. (When you don't see a Library folder in you home directory in the Finder, right-click Show View Options or from the menu bar View > Show View Options and tick show Library)) (Move to /Library/Keyboad Layouts/ for global usage.)
11. Restart your computer 1.System Preferences > Keyboard > Input Sources > add your language

For more bundles see here