I just wanted to report back that I have things working now. My first attempt was furlong47's suggestion, which did work; it took a few steps to get it into AP, but I did get it in which is more than I was able to do before. I tried the link that soonerjcb gave (the connect.garmin link) but I got a 404.
Ken's link https://attackpoint.org/garmin-connect-setup.jsp
didn't work on my desktop; I tried it with two browsers (Google Chrome, and Mozilla Firefox), and in both cases, I got a spinning wheel that never stopped even after waiting for several minutes. But when I tried it on my phone, it worked fine, and I'm now linked automatically between my 235 and AP. I did a walk/run this morning, and when I logged on to AP, it had magically been entered. So thanks again to everyone who offered advice!