O2 Sensor Heater Circuit Bank 1 Sensor 1 (P0135 error / fault)

After a recent service I was told by my local Skoda service centre that my Kodiaq required a new O2 sensor. I did not have it replaced at the time seeing as they quoted me something like $900 for the parts and labour. I was told by another mechanic that its not an emergency issue but should get it sorted sooner than later. 

I've since discussed with the alternative mechanic about looking at doing the replacement for me but am struggling to find an exact part number. Skoda only gave me the initial quote over the phone - I have since reached out to try to obtain an email copy hopefully with the part number but yet to hear back. 

Are there any ways to find the exact part number here aside from getting that quote?