Connecting phone to TV (as in television, not tow vehicle)

I first tried it with apple tv and wifi but apple tv doesn’t have a way to interface on a website, I changed to Roku which gives you a code to enter on the tv and that worked but campground wifi doesn’t usually have the bandwidth. I can stream to my ipad or use it as a hotspot if I have cellular. Other than that you need to download to watch. Unlimited cellular can be a problem because after a certain amount of data used they step the speed down.