That's not the debug, but the issue is right here (Note: I've removed the formatting characters):
As for which mod iapg is, I have no idea, whoever wrote the mod is unhelpful by not making their mod id identifiable for their mod
It looks like you might have a mod in the folder twice, please provide debug.log for more info. (Please note the preferred method of posting logs listed in the "Logs" section of my signature below)
To me it looks like that is the log for a single task instead of the full log.
If you're getting the log from Intellij's Build panel, select the topmost option from the left column of the Build Panel to show the full log on the right
Those are two completely different issues.
The first one is the 1.16.1 mod not having something that was optional in 1.16.1 but required in 1.16.2.
The second one is a mod that's not updated to deal with a breaking change in recent versions of Forge.