Hello.
About 6 years ago, tired of always having to change the interior light bulbs of the supplementary brake light and even after having changed them continue to struggle with the horrible bulb holders that created intermittent lights,
I set out to carry out a complete replacement.
I found an additional led light that fit completely on the original base.
(I don't remember where to buy it)
it was enough for me to extract the anchoring supports of the new LED and insert it in the base of the original, the wiring is child's play.
The original brake light unit is sealed, I used a very fine hacksaw blade to separate the red side from the base/socket but in the end it wasn't worth it.
The one in the link is something like this, it's better to extract the original, measure it and be patient and search the internet for a replacement of the right size.
https://www.carbuilder.com/uk/led-high-level-stop-light-with-swivelling-feet-210mm(this is the model, there are different sizes, you just have to find the right one)