Hi,
You have created new PO document type ZLOC- so add this value in PO document type release characteristic in t.code CT04 and then update this change of PO document type release characteristics in your PO release class in t.code CL02 and save.
Now add this new document type value ZLOC for your PO release strategy in t.code CL20N/CL24N for your PO release class with release group.
Regards,
Biju K