You want to redirect every user always to EntraID?
Then got your authentication flow, find the “Identity Provider Redirector” and configure it ( symbol) to use always/default your IdP alias.
The difference between the two solutions is that the first one will achieve the desired behavior for only one specific client (the one specified in the redirect URL to Keycloak), whereas the one proposed by @dasniko will redirect all client applications to the external provider.