I just built my first rack and I'm going to use 4" flexwatt belly heat. This is my first time doing it, and I was wondering can I wire it up to have only one outlet?

My shelves are 2ft long and there are five of them. I wanted to have the flexwatt on each shelf then I would connect them together with using extension cord but I will only have one plug at the end. Am I making sense? lol. Anyway help would be greatly appreciated. Thanks.