La. Code Civ. Proc. art. 4703
Current with operative changes from the 2024 Third Special Legislative Session
If the premises are abandoned or closed, or if the whereabouts of the lessee or occupant is unknown, all notices, process, pleadings, and orders required to be delivered or served on the lessee or occupant under this Title may be attached to a door of the premises, and this shall have the same effect as delivery to, or personal service on, the lessee or occupant.
La. C.P. § 4703