Navigating to your Boundary Enterprise control plan shows a sign-in screen without a login prompt
This occurs when Boundary Enterprise does not yet have an auth method enabled. This can be accomplished from the command-line using something like the following (specifying values unique to your environment):
boundary auth-methods create password \
-recovery-config /tmp/recovery.hcl \
-scope-id <org_scope_id> \
-name 'my_method' \
-description 'My password auth method'
Please note that you will need to create a scope for the auth method to be created in, and subsequently will need to create login accounts in that auth method.