Unable to login with api using keycloak oidc user

I have setup keycloak odic authprovider for rancher and i have created user on keycloak.
Using the GUI i can connect to rancher using the keycloak odic.

When I try to do the same using the api it doesn’t work
i have try to generate directly a token from keycloak protocol/openid-connect/token but the generate token is not recongnized by rancher i got an authentication failed when trying to use it as BEARER token

When I try to usr the rancher keycloak oidc provider url from the public api (v3-public/keyCloakOIDCProviders/keycloakoidc?action=login) i got 404 error on the redireection to rancher verif-auth url

I understand that everything doable from the gui can be achieve using the API.
What is the correct workflow to authenticate with a keycloak user to rancher using the API? any documentation or example around?