Since aphantasia is a bit of a spectrum, I have it to a decent degree as I can only imagine blurry images in my head. I only learned about it doing some psychological testing when it was a test my psychologist wanted me to take. I can only speak for myself as I don't know anyone else with the same kind of condition IRL, but in general I just sort of memorize task order for repetitive things. I imagine you do the same, but you have visual cues memorized in the same way I just know the steps to do something. It's not like I don't recognize what I'm looking at when it's in front of me. I tend to think of it as having to be very analytical when doing one of those "spot the difference" image puzzles. I know both images have a potted plant, but it's easier if I have them side by side to know that one was a succulent and the other was a fern. I don't know if that analogy helps you. I don't know what it's like to have a vivid visual imagination, so it's the best metaphor I can think of at the moment.

I have done remote tech support for software that I wrote which was pretty difficult if I couldn't look at it myself locally. At least for me, I can know the properties of something such as a friend having long, red hair, but I couldn't just visualize their face. I would still recognize them immediately when I see them. If it's something like a tripped breaker, I just know to tell the person which room to go into and what a tripped breaker will look like so they can identify it themselves. It's not like you don't have a memory, but for me the visual parts of those memories are just too blurry to describe that way.

I can read fiction just fine, but it helps if the characters are illustrated in some kind of way so I know what I'm supposed to imagine while the action is happening. That could even just be a single picture of cover art. At least for me, I can still picture a cobblestone street, but I sort of just see a lot of beige or gray things in my mind with almost no definition. From reading online of the 1-5 scale of aphantasia and comparing it to the test results I got back in percentages, I think I'm somewhere between a 3 and a 4 for levels of intensity if that helps to clarify my perspective at all.

Apologies for the essay response, but I hope it helps to understand! If it's any consolation, I find it kind of ironically hilarious that I can't imagine having a vivid imagination.

ETA: It looks like the original test used 1 as completely unable to imagine things and 5 to a vivid imagination. That scale was flipped for the second version of the Vividness of Visual Imagery Questionnaire. My scale of 1-5 is based on the second edition, I am on the lower end of the spectrum of vividness, but I can still sort of imagine things to a certain degree.