I don’t know, perhaps something I don’t have set up or they’re just being nice, this is what I got;
Sticking the details into 發票查詢 - Amego 光貿電子發票加值中心 lead to being able to download a pdf of the receipt which then could be printed (2 side printing A4 only!), alternatively there was some way to connect to an App and get paid through that but I’d had enough of electronic “convenience” by then and just did the caveman print.