How can I use my iPhone on my Samsung tv?

You can’t. The fire stick does not support Airplay. If you have a smart Samsung that supports Airplay you don’t need the fire stick.

I’ve read that there are 3rd party apps for iPhone that can mirror the phone to a fire stick, but I have no experience with them.

The TV must be a “smart” TV that supports the latest version of Apple Airplay.

I want to connect my phone to the Samsung TV but I can’t