As mentioned it is probably bent. I have had this before. The metal is malleable and it can be easily straightened.
Another possibility...the trigger/bolt spring screw is not seated deep enough, thus not allowing the triggerguard to seat flush.
It could be bent... or it could just need the other trigger assembly screws loosened and then all the screws including the front screw retightened a little at the time.
I’ve found guns with trigger guard and /or back strap to trigger guard or main frame gaps due to loose screws or assembled sort of out of order.
I’ve got a few older uberti guns that seem to be persnickety about which screws get tightened in certain order.
I hope that's just a shadow around the right half of the trigger screw hole. The photo makes it look like the hole is too big for the head of the screw.
If the trigger guard was bent, the gap would be in the middle and both ends could still be tight.
The screw is loose or missing altogether.
It isn't a loose screw. One (or even two) loose screws won't show a gap, the fit will still be flush. It's bent. Doesn't seem it would be that hard to "unbend" since I doub't the trigger guard is that hard. But you have to wonder what kind of abuse was it subjected too to bend it like that. I'm looking at Mikebiker and I still don't see how you could do that.