I want to watch a Zoom class on my TV but cannot figure this out. Airplay on my IPad can’t find TV. Both are on the same WiFi, both update automatically. TV is an LG, less than a year old. Help this poor senior citizen!

I am trying to figure out how to cast a zoom class onto my TV. The TV is an LG less than a year old and my iPad is a couple years old. Both appear to have airplay. I have checked and they are on the same Wi-Fi network. The iPad is unable to find the TV. Both of them have their software updated automatically so are current. There is also a Roku attached if that makes any difference. I remember trying this about six months ago. I was able to get pictures on from my photo album but nothing else. I’ll be darned if I remember how and it’s not working now. Any thoughts on what could be wrong? I don’t think this is supposed to be this hard. I’m wondering if it’s something painfully obvious that I am missing, like needing to have my TV set an a different source or something. Any help that you can give this poor senior citizen would be appreciated.