Source: https://bsky.app/profile/funnysnarkyjoke.bsky.social/post/3lmkfwebeuc27
In fact you can use your smartphone to change the channel on nearly any TV. In the comments on that post some people talk about how to do it. Basically you need a smartphone with either builtin IR or use a USB-C IR blaster or if your phone has a 3.5mm headphone jack you can also try one of those but I’m not sure if the 3.5mm ones are as commonly supported.
How do you know if your phone has built in IR?
GSMarena has specs for most smartphones including infrared (listed under connectivity).
Here’s a link to a search showing all phones in their database with IR: https://www.gsmarena.com/results.php3?chkInfrared=selected note I haven’t checked accuracy or completeness, it might be best to check the specs for your phone or search if your phone supports it.
If you got an old phone or an old PDA it might have IR if your current one doesn’t.
Check the specs or look for the blaster with another phone
edit: forgot that it’s only visible when on, so just check the specs/apps