i have 3 questions

1: for co-oop runs is aternos allowed, if not what are some free hosts that can be used

2: for fabric loader what do i need to show/ do i need to show the mod folder or anything like that before starting the run?

3: can i use the SpeedRunIGT mod's recording for the runs? if yes is there any specific settings?

You should ask in that game's forum or Discord, or ask that game's moderator(s). Or read that game's rules