My 2021 T6.1 key fob is looking worse for ware and I was looking to see if I could get a replacement. It has three buttons, the middle one unlocks the barn doors. I ordered what I thought was a replacement, but after dismantling it all the circuit board does not fit as my fob is wider and shorter. 
Does anyone know which case I do need for this, don’t really want to pay a dealer for another key when it’s only the case that’s worn.

Does anyone know which case I do need for this, don’t really want to pay a dealer for another key when it’s only the case that’s worn.