Redirect to external login page

How can we redirect users to an external login page instead of the Okta sign-in page when utilizing the Okta OAuth redirect model in Vue? Currently, our application checks if the user is authenticated upon access and employs the signInWithRedirect() method, which ultimately directs users to the Okta login page. However, we aim to fulfill a requirement by redirecting users to an external login page. What steps should we take to achieve this?