Going to the "source", the Debian package is available directly from Mozilla at
I don't mean to confuse you, but if you want to get into the larger discussion of avoiding SNAP packages, the following posting is only one of many on the topic, may provide some insights:
I'm not sure that it is "safe" to remove all SNAPs, but that is up to you to decide.
On the topic of Firefox, Thom ( @tkn ) has raised the idea of Librewolf as being a possible better Firefox "clone", which is what I am looking into for myself.
I just started to look at that, and it may take me a while before I decide, so I hope you won't be waiting on me to come back and report on a yea or nea on a possible Librewolf adoption. 