Minimum bet for bonus?

I always see those slot bonuses that say you need to wager a minimum per spin to qualify, but the actual minimum isn’t always clear. Some T&Cs just say “qualifying bet” without getting specific, and sometimes you’ll spin at 20 cents and find out you were supposed to do 50. I usually check with support, but you know how reliable that can be.

Curious what everyone else does to be sure they’re not spinning below the minimum and missing out? Do you just always go over the min bet for safety, or have you found a consistent way to check the actual required amount for slot bonuses?