Specialized Allez Sprint Fork
Aftermarket forks are available for pretty much any bike frame.

To fit the frame there are three things to consider, length, steerer diameter and taper, and brake mounting.

The length is usually measured 'axle to crown', which means the center of the axle to where the fork meets the frame head tube.

The steerer diameter and taper (larger size bottom bearing) have to match the headset bearings in the frame. I believe the 2019 Allez Sprint has a 1-1/8" to 1-1/2" taper steerer.

Obviously you need either a rim or disc brake fork.