Hi Pavan,
You can bypass the login and consent screens by providing an id_token (as id_token_hint) and setting the prompt value to none.
i.e:
https://ssg:8443/auth/oauth/v2/authorize
response_type: code
client_id: 5eed868e-7ad0-4172-88f2-704bcf78b61e
redirect_uri: http://<server>/callback
scope: openid profile email user_role
prompt: none
id_token_hint: <valid id_token)
I am not sure I understand the full requirement, grant_type=password refers to the resource owner password credentials grant which utilizes the /auth/oauth/v2/token endpoint so the authorize endpoint would not be involved in this case.
OAuth Request Scenarios - CA API Management OAuth Toolkit - 3.5 - CA Technologies Documentation
For using an external IDP you can refer to this:
Support Optional Authentication Mechanisms - CA API Management OAuth Toolkit - 3.5 - CA Technologies Documentation
Regards,
Joe