Quick question to figure some stuff out with calorie counting

So I’ve been using my fitness pal to track calories and I’m a cyclist and been getting a lot more miles down. My question is right now my target “base calories” is 2890 I think for my original goal. I generally eat at or a little under most days. But I also will burn 500-1500 calories on a normal day riding my bike. Today for instance I burned 1100 and it takes that into account on the app. Are those essentially supposed to be extra calories I am able to eat or should I still aim for just the 2890 calories the app offers?

Every night when I “complete” my day it tells me my weight in 5 weeks will be much less than my current goal. Which I’m not opposed to but at all because my initial goal I’ve already almost hit in about 3 weeks. Long and short can I have a 210 calorie bag of popcorn and go over my base goal calories even though I have a 1100 surplus from my ride?

I have dropped about 10 lbs in 3 or so weeks I know a bit will be water retention, I’m just new to calorie counting and trying to figure out how to account correctly. Appreciate any help!

And as a PS the calories burned I think are fairly accurate I have a heart rate and power meter and googling my effort time and weight seems to give a similar number. I still grain of salt it and I’ve never went over my base and calorie outage(until I do my first event of the year a lot of beer and pasta will be consumed before and after 😂)