I have put my app into review but it gets disapproved because it first goes to my standalone shopify app and then the app redirects to the oauth login if not installed or to the homepage if they are installed.
I don't understand how i can "immediately" get to "https://example.myshopify.com/admin/oauth/request_grant" IF I don't know the shop name?! I have to get that information from the url params when they land on my page. that's why i do the redirect AFTER i know if i have the shop parameter etc.
Order of events in my code. Using reactjs frontend with axios calls to an express backend.
-land on the shopify_login_page and on page load runs this function: