Record search for Grandfather WW1 for a Citation for gallantry at Samark. Not in NAA under his service No. with no idea which direction to go. We want to follow up for medal if possible

Questions and answers
1

Grandfather received a Commendation at Battle of Samakh WW1 for gallantry while under fire. Cannot find in NAA record search with his details which avenue to go for this paperwork. Want to follow up with possible medal which he did not receive.