the backtick ( ` ) is a dead key on the French Mac keyboard; that is to say that it does not generate a complete character, and that you need to type another key after having typed a backtick for it to show as a single character.
https://www.foobarflies.io/backticks-on-the-mac-keyboard/
Unfortunaly the offered keyboard layout bundles in the blog post do not seem to work properly with more recent versions of Macbooks.
Using Ukelele I modified a copy of the original French layout delivered with the OS of my Macbook Pro 16.
- Download the
.bundle
folder (it will be displayed as a file on the Finder) - Keyboard preferences
- Input Sources
- Click the
+
button on the bottom left corner - Select the
French (backticks)
layout