Arguing for Orthodox Judaism (continued)

I’ve asked this before but I’ll ask again because it’s more contextually relevant, I asked how to convince non Orthodox Jews of orthodoxy and you said to show them, but in a context where you can’t or they won’t engage then what arguments can one put out that orthodoxy is the only authentic tradition (for example I know a pro abortion reconstructionist woman who says the past has a vote not a veto, or reform Jews, or conservative Jews who say they’re halachic and that gay marriage is kosher because some conservative rabbis interpret the Torah that way etc)