Question Using TV as a bluetooth speaker

[JamJamJames]

Hi there,

Sorry if this is a duplicate but i couldn't find a question like this.

So i currently have this samsung TV UA55RU7100WXXY

Series 7 55" RU7100 4K UHD TV* | Samsung AU

Samsung 2019 UHD, RU7100, Deliver the essential UHD with Smart

www.samsung.com

I wish to use it as a Bluetooth speaker, so I thought to use a receiver like this

https://www.amazon.com.au/SZMDLX-Bluetooth-Transmitter-Receiver-Headphones/dp/B07TP6H3HW

Which can convert a Bluetooth input signal to 3.5mm AUX audio output, but the problem is my TV has no AUX input.
I then purchased a 3.5mm female to 2 RCA male cable to plug into the back of the TV, into the Component/AV input but the TV wont detect any source (i assume because there is no video input)

https://www.amazon.com.au/dp/B09SRXZGD6?psc=1&ref=ppx_yo2ov_dt_b_product_details

I guess i am wondering has anyone else tried this specific use case? And if so, how did they approach turning their TV into a Bluetooth speaker?
(Maybe i should be trying to use the HDMI input instead of and Component/AV input? If so, is there a hdmi adapter that takes no video but audio?)

Thanks!