Error 400 w/o detail for authorize request

Hi!
I am trying to implement SSO with Okta OpenID Connect. My app would redirect the user to the Okta login page. But for my request

https://dev-329009.okta.com/oauth2/v1/authorize
?client_id=0oan703fu7Fw36XJC4x6
&redirect_uri=http%3A%2F%2F192.168.31.198.xip.io%3A8000%2Fadvanced%2Faccounts%2Fproprietary%2Flogin%2Fcallback
&scope=openid
&response_type=code
&state=HHKCZq30druj
&nonce=g5ly497e8ps

I just get “400 BAD REQUEST Go To Homepage”. That’s all. No error code. Nothing. All the references suggest checking the error’s detail… but there’s no any slightest suggestion.

I tried to find my request in logs by ID with a query string

request.id eq "XyE78MgRAN-bGRH7jAErLwAABYc"

but in vain - the query string should be something different… but how should I format it?

I set up a web application like this: