Articles properties - txn replication

Hi,

I am doing a replication for just a single tbl tb_customer which has
customer_code as the PRIMARY KEY

I have done a txn replication with the articles properties --> snap shot
defaulted to clusterd indexes & non-clustered indexes being ticked. The
tb_customer tbl does not exist in the subscriber when replication first
started ...

after replication found that the P.K was somehow not replicated across -
with the above settings is it correct not to replicated the P.K structure ?

later i go change in the articles properties and included "include declared
referential integerity". i deleted the tb_customer from the subscriber and
try the replication, this time the P.K was replicated across. shld this be
the way ?

earlier i posted a similar and was told there's "enforce replication" that
allows P.K to be replicated but could not find where this option is

could anyone kindly advise ?

tks & rdgs