Composite key with a foreign key(one to many)

I have two entities one as a header entity and Items Entity!
e.g 1. order_header( orderNo(pk), description, date, etc…)
2. order_items(orderNo,itemNo, description, unitPrice, etc)
In this scenario I have orderNo(natural key) as PK in Header entity which fine, now my challenge is how to make a composite key of order_items(orderNo,itemNo)?
The cardinality is one-to-many.
if there is a already something on the forum on this please share a link.

Thank you.

How to link entities using a part of Composite PK was described several times on this forum.
See this topic for instance.