How to edit label text in Wix Code?

Hi, I’m trying to do something similar to this thread. As my product is sold per metre, I would like the ‘Quantity’ to read ‘Quantity (metres)’. Like the person above I have searched for the elementID but can’t track it down. I’d rather not have to attempt to write a whole new quantity input if possible. Would it be possible to give me the elementID or tell me how to find it?

Thanks for any help in advance.