Do I need to define my own callback function pointing to https://<grafana_domain>/login/azuread

I am following this tutorial to implement : Configure Azure AD OAuth2 authentication | Grafana documentation

I have added and as redirect uri. I am starting the azure application as a docker image in port 3000. The configuration file is as follows:

name = Azure AD
enabled = true
allow_sign_up = true
auto_login = true
client_id = 
client_secret = 
scopes = openid email profile
auth_url =<tenant_id>/oauth2/v2.0/authorize
token_url =<tenant_id>/oauth2/v2.0/token
allowed_domains =
allowed_groups = grp1 grp2
role_attribute_strict = true
allow_assign_grafana_admin = true
skip_org_role_sync = false
level = "debug"

I am curious to intercept the access token . I know that we get the authorization code from auth_url and then we send it to the redirect uri and somehow the token_url is used for authentication.
I wanted to know do I need to implement my own callback function overriding the route /login/azuread .
I tried looking for the inplementation of /login/azuread inside the docker image or the github repo but didnot find any .
So, my question is do i need to implement my own api that will capture the authorization token and forward it to token_url.