As already posted, with very few exceptions front hubs/forks are 100 mm wide. I've only worked on one that wasn't. If you post what kind of bike it is maybe someone can tell you if it might be one of those rare oddities or if there's something wrong.
Seen a couple more intended for thinner axles though. Dropouts can easily be widened with a file and some attention to detail. You want to remove an equal amount of metal on both sides of the slot.
It might be possible to remove the part that the green arrow is pointing at and then move the outermost part with the knurled face up against the bearing. Knurled side facing out. If you do that, make sure you have enough clearance between hub flange and the fork leg(s).
Ideally you should remove the one on the other side as well, or your wheel will not be properly aligned.
Bike will still be rideable, but might wear tires unevenly and pull a little to one side.
If removing both makes the hub too narrow, you can leave one in and have the wheel redished, but that'd basically be deliberately creating another maladjustment to cope with the first maladjustment.

The axle(the black threaded bit) is the part that should go in the dropouts.

If it's a steel fork it can be spread instead.

While simple in theory it can still be done badly by the unlucky/unwary. By merely pushing the legs apart there's no guarantee that both will bend out in equal amounts. A bit more finesse is recommended.