Refinishing a wooden door?

Oil based polyurethane works fine if not in direct sunlight and the added benefit is you can get it in different glosses.

The ultimate protection, in my opinion, is Marine Spar Varnish and you can get it in glossy or semi gloss with certain manufacturers. This is the product used on refinishing wooden boats.

It’s tricky wood moves finish doesn’t that’s why it delaminates
Look for an outdoor hard wax oil that you can apply and then annual add a maintenance oil which both are Han rubbed in you can do it in no time but it’s penetrating it doesn’t sit on the surface and won’t delaminate usually about 100. a liter some have an isocyanate hardener you don’t want that type.