With the version 130, Mozilla introduces a new navigation bar in Firefox for Android. If you don't like it, you can disable it in the "Secret Settings".
I was not a fan when it popped out on my screen. But, after sometime, it's pretty useful and saves a tap on the three dots button.
You need to enable the debug menu by taping multiple time on the Firefox logo in Settings -> about Firefox.
Once the debug menu is enabled, you will find "Secret Settings" in the Settings.
Oh wow! I didn't know this. Thank you.