Enter the shared password to continue.
This is an internal tool. Open it from the Shopify admin — Apps › Customer link generator — and you'll be signed in by your staff account.
There's no password for this one, by design.
The Shopify admin session wasn't accepted.
Type an order number to build a link that's already filled in for the customer.
Order number, with or without the #. Pasting the order's admin URL works too.