Players face is empty when changed

I am trying to change the players face from an id on the roblox website using a script, however, the players face is always empty. I’m pretty sure this is because I have the face id and not the decal/image id, but I’m not sure how to get it.

What I am doing:
game.Workspace.TheMightyScript.Head.face.Texture = http://www.roblox.com/asset/?id=20418658

There are no errors, the face is just blank. I’ve checked everywhere, but I can’t find any scripts that would find the decal/image id.

Try this, http://www.roblox.com/asset/?id=20418518

This didn’t work, I ended up just using https://www.roblox.com/asset-thumbnail/image?assetId=20418658&width=420&height=420&format=png, it’s probably not the best way to do it, but it works.

The proper format for any asset is rbxassetid://id. More information can be found on the Content article on the Developer Hub for working with ids.

http://www.roblox.com/asset/?id=20418658

The id was wrong

(Or, rbxassetid://20418658)