Blazor webassembly shows 405 error in localhost (and also when deployed to iis) when redirect back from payment website

Question

I have created a blazor webaseembly project using .net 7. The blazor app redirects to an external url for payment. Once payment is done the payment status page(which is in the blazor app) should be loaded as that's the return url set while calling the payment gateway. However, when the payment status page is showing HTTP ERROR 405. Need urgent help.

Answer 1

redirecting to the payment gateway will unload the blazer app. the blazor app should save any required state before the redirect. the reply url to the payment gateway should be a valid blazor page. when this page loads it should restore state.

if the gateway responds with a post, then the reply url should be an action on the host for the blazor app. after processing the post data, it should redirect to the blazor page.

Answer 2

Finally was able to fix the issue. The payment gateway return url should be an endpoint in API rather than blazor application. Once the return url lands in the API then load the blazor application from the API using RedirectPermanent.

return RedirectPermanent("https://yourblazorwebsite/paymentstatus");

Here I wanted to show the payment status to user after the payment is done. So I used the RedirectPermanent method inside my API. The blazor application then loads the payment status page with all state intact.