Sign in
Each restaurant has its own address on .loopbystlr.com. Open the link your restaurant shared (for example https://yourstore.loopbystlr.com) and use Login there — the site already knows that store; you don't need to type a store name.
Know only the store code? (advanced)
If you don't have the full link, you can open sign-in using the store code and this site's routing.