Hi Lalee, WHY do you need 5 meters ? In my humble opinion, you don’t need a light all the way along the outer edge at the back of the television, especially since a very bright effect will be more of a nuisance than an aesthetic feature. Position your light at least 10 cm from the edge. If the wall is close, it can also serve as a support. If someone has actually installed such a system, he will advise you on the best solution.
I would recommend building one, but one that long is likely to have issues with power draw. You’d likely need multiple strips connected to a controller instead of one giant LED strip.
Thanks to everyone for the replies!
In the end, I bought a Govee Strip Pro 2, and I’m using the Govee Home app (Win 11) to mirror the colors onto the LED strip!