Just screen mirroring iirc.
For reference, I have a Samsung S23, and I use the Smart View function that you can find if you pull down twice the top of the screen and get to the Quick Settings drawer. I think my phone and TV had to be on the same WiFi network at first for the phone to be able to find the TV, but after that I can turn WiFi off on both devices and Smart View still remembers the Roku TV.
Oddly, after screen mirroring begins and I can see my phone screen on the Roku TV, if I scroll down on the Quick Settings drawer it shows the phone’s WiFi is on, but the symbol next to my signal bars is clearly 4G LTE or 5G and not WiFi.
Works pretty well unless you have too much ElectroMagnetic Interference (EMI) in which case the lag sucks and may even cease the connection. I’ve been using screen mirroring for years though and it’s great.
Good luck!
A given group of people are not a monolith. While we do share a lot of similarities, we also all have the potential to be a little different from one another.
I hope you get a chance to find someone that will allow you to be open like that again. Sharing those emotions and having someone their to empathetically receive them is one of the most gratifying things as a human.