Use text replacement in firefox

Hello, I am inquiring how to setup text replacements in FireFox i.e. TY = Thank You

It is the same exact tool on Mac OS Mojave in Preferences - Keyboard - Text

I would like to setup some per-defined rules that automatically change my text as I type. For instance, when typing "TY" in Firefox, when I hit the space bar, I would like it to promptly change the "TY" to "Thank you" (without quotes).

This would help a lot with my productivity at work. I am not sure if there is a way to enable my text replacement shortcuts setup on my Mac to work in Firefox, or if there is some sort of Add-On that would achieve this.

Any help here would be greatly appreciated!