Also, you might spend maybe 200cal lightly cycling during a zoom call. You will get that back in a few seconds of eating, if you choose something heavy like a chocolate bar. Your best bet then is to just control the incoming calories, because even an all-out workout of an hour will do you maybe 800cal if you're a bit bigger and stronger than me, and even if you did that you'd feel super tired for a long time after and maybe even decide to eat up that amount again.
In my case, it was all about calories. I've done this, and a friend did this as well: get one of those electronic scales that's got a couple of decimals on it, eg says 92.15kg. Then you can get used to understanding how much weight you lose while sleeping, how much you are carrying as pee and poo, and how much a meal tends to weigh. This will tell you how much you actually weigh, because you can take out the noise.
Have a look at an online calculator that tells you how much you should be eating for a given target. Find out the calories in everything you eat, and eat that budget.
I did this, and amazingly, the weight loss was just as expected. Thermodynamics seems to work.