These heavy duty self-healing injection ports have a deep well, with 13 mm diameter opening, 9/16″ across the top and and 9/16″ top to bottom. Drill a 15/32″ or 1/2″ hole in a canning lid and insert. (It’s best to drill a smaller 1/4″ hole first, then expand to the larger bit size.)
Good for dozens of repeated uses!
Buy a ready-made lid here.