Walgreens RR vs Cash confusion

I've gotten a different answer every time I've asked a Walgreens employee.

When I go in the store and purchase an item that has a register reward, is this simply a coupon to use on specific items in-store? They said I could use it on anything, but then the printout clearly said it was only for specific brands.

If I had purchased that item online as a pickup instead, would that have been Walgreens cash for any use instead of a specific brand?

Thanks for any help you can provide!