To unlock the Let me help you trophy in WWE 2K19 you need to assign the Auto-Reversal Payback ability to a wrestler and use it three times in one match. It's best to set the difficulty to Easy.
It seems that you can complete this on any match type but Iron Man is recommended as the match won't end after one fall, but after a set time. 15 minutes should be enough to get the trophy but you might want to set it higher.
Make sure you set your wrestler's yellow Payback ability to Auto-Reversal before you start.
Because you're in an Iron Man match, the easiest way to get your yellow meter up is to just get pummelled and pinned a lot -- it doesn't matter how many times that happens for the purpose of this trophy.
Once your yellow meter is filled (and the red meter is starting to fill) just hold R2 whenever you are grounded for an opportunity for an auto-reversal of the opponents follow-up move. It won't trigger if they go for a submission or a pinfall so let those play out, but if they go for a grab or a stomp holding R2 should cause an auto-reversal. You just need to fill that yellow bar twice more (by getting pummelled) and use auto-reversal again to unlock the trophy.
Here's a helpful video guide from Poru99: