My dad likes to remind me that he was 'working remote' (had a dial up modem and two factor auth in to whatever he was doing at AT&T/Ameritech) back in the early 2000s
I also recall getting an ISDN line in the late 90s, but I was working in an office at the time.
Worked from home before that '90/'91 but not online. Had an IBM cash register in my bedroom for which I wrote a POS application.