You can get one in the Clothing Store in Varrock for 2gps or ask someone

Now go into the little WOW Gold shack where Luthas lives (next to the banana trees and the closest house to the port). Ask him for work. Now go outside and pick 10 bananas from the banana trees.

He’ll tell you that he is in charge of shipping the bananas to Wydin who owns a grocery store in Port Sarim. Talk to one of the sailors to go back to Port Sarim. Let them search you.

Now if you’ve already have an apron, put it on. If not, you can get one in the Clothing Store in Varrock for 2gps or ask someone around if you can buy one from them.

When you have an apron, go to the grocery in Port Sarim. The grocery store is near the Fishing Store. Go into the door that leads to the back of the grocery. Search the crate to get the bottle of Karamja Rum.

Head back to the pub and talk to Redbeard Frank. He should give you a key that will open Hector’s chest. Then go to Varrock. Head into an inn called the Blue Moon Inn. The inn is in the southeastern part of Varrock. In the bar is a ladder. Climb up.