Can you send pictures so I can confirm that it is apple scab?  It is not very common here and since we have been so dry, it is more unlikely, unless irrigation hits it.  Please send cultural details like watering and application of any products.
Thanks,

Crabapple is planted in lawn. Lawn watering occurs Tuesday and Fridays, 25 minutes each of these days. Water does not arc in air and hit leaves. Tree gets sun for about 70% of the time.  Tree is 2 years

This is definitely not apple scab. I see some minor insect feeding- the tiny, tiny little white spots, nothing to worry about. I see a little bit of nutrient deficiency. I would do a nitrogen fertilizer application after the leaves drop in fall.    This is good to get them off to a good start next year. I would avoid any weed and feed and only spot treat weeds or dig them out. And being in a lawn, you want to make sure that the tree is occasionally (about every 10 days in the heat of the season) getting a deeper watering to a depth of 12-18".   Make sure there is no mulch within a foot of the tree so with the more frequent lawn water that the base of the tree can dry out to avoid crown rot.  https://cmg.extension.colostate.edu/Gardennotes/635.pdf