There may be a way to re-map keys within Budgie without having to use another piece of software to do so. You're looking to customize your keyboard layout. I'm familiar with this from having to do the mirror of it, remapping keys on a Mac to use Windows keyboard bindings. For me, the Apple key was where I expect left Alt to be.
In Plasma (an alternative to Budgie), for instance, there are settings in Keyboard > Advanced where I can tell the system that for the Alt and Win keys - Ctrl is mapped to Alt, Alt is mapped to Win. (Win would be the Apple application menu on a Mac keyboard). I looked through the Budgie keyboard settings but I didn't see how there. You might try asking the Budgie folks through Matrix if there's a way to do this.
If you still want to install Kinto, you would need to go to the repository pomon linked and follow their installation instructions. I had a brief read, and they aren't the most beginner friendly.
It's dependency xkeysnail can be installed on your Solus installation from source, see their
website for Solus install instructions.
After you install xkeysnail, you will need to install Kinto from source, following the instructions on their page.
If you contact the developer of that software, they can help you get it installed.
