Switch user organization with out re-login in asp.net Core

I am encountering an issue during a silent login attempt, despite having provided all the relevant information. An error is still being returned.

var client = new RestClient($"{_options.Domain}/authorize?response_type=id_token token&client_id={_options.ClientId}&redirect_uri=https://localhost:44304&state=STATE&scope=openid profile email offline_access&nonce={nonce}&audience={_options.Audience}&response_mode=form_post&prompt=none&organization={organisatoinId}");

Furthermore, the return status code is “OK,” but upon inspecting the content, an error is displayed in HTML format. This is contradictory to the documentation, which clearly states that a redirect URL should be returned instead.

<html><head><title>Submit This Form</title><meta http-equiv="X-UA-Compatible" content="IE=edge"></head><body onload="javascript:document.forms[0].submit()"><form method="post" action="https://localhost:44304"><input type="hidden" name="error" value="login_required"/><input type="hidden" name="error_description" value="Login required"/><input type="hidden" name="state" value="STATE"/></form></body></html>