Direct Login to forms in eBusiness Suite

The usual url for loggin in to Oracle Application is
http://<server name>:<port>/
which most of the times gets directed to
http://<server name>:<port>/OA_HTML/AppsLocalLogin.jsp

But for some reason or for troubleshooting purpose we may need to login directly to forms.
Below are the urls for directly connecting forms.

RMAN-06091: no channel allocated for maintenance (of an appropriate type)

RMAN-06091: no channel allocated for maintenance (of an appropriate type)
The error message appears when we try to delete some backups. Set of commands could be like below.

RMAN> show retention policy;
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 7 DAYS;
RMAN> delete obsolete;