To search for disc golf stores in the UDisc mobile app, tap the ...More tab and then scroll to Disc Golf Stores.
You'll see a map with local stores, and at the top is a search bar into which you can type any store name or location, and then find stores that sell disc golf equipment that way.
You can check out the disc golf stores directory online as well: https://udisc.com/stores
If you'd like to add a new disc golf store that's not yet already listed in UDisc, then keep scrolling down a bit via the ...More tab of the app, then tap Add Store. You can add a store online as well: https://udisc.com/stores/add
Here's a blog post with some additional information on disc golf stores in UDisc: https://udisc.com/blog/post/explore-the-worlds-disc-golf-stores-with-udisc