Older Av ?( red yellow white connection cord) dvd connect to tcl 55 roku with only hdmi ports. Bought hdmi to composite av adapter ! Nothing! I wasnted even aware tvs are supplying these cord ports anymore rented a movie i can even watch! Beyond frustrated
You say you bought an HDMI to composite adapter, but what you would need would be a composite to HDMI adapter. (ie: these gadgets tend to be unidirectional.) It might make sense to just buy a more modern player instead. Blu Ray players came out in 2006, so I wouldn’t be surprised if old ones are already showing up at Goodwill stores.
My 50" TCL Roku TV has a small yellow "AV IN" port. Are you sure yours doesn't? It requires a special cable which I don't believe they supply in the box.
Something like this:
https://www.amazon.com/Video-Component-Adapter-Cable-Replacement/dp/B08B81QV6V/
Otherwise you need a Composite-to-HDMI converter as @Strega mentioned. Something like this:
https://www.amazon.com/Converter-BD-Composite-Adapter-Blue-Ray/dp/B08W98BD6L/