Dorm Room Question-- Please Help with memory foam topper

So, I recently bought a memory foam topper as well as a bed bug mattress protector sheet… So my question was do I place the memory foam topper on top of my mattress after I have enclosed my mattress with the protector sheet and then put normal sheets over the topper OR do I place my memory foam topper directly on top of my mattress and then enclose it with the protecter sheet and put normal sheets over that? I’m so confused lol

Topper first and then the cover to hold it down. :-*

Thank you!! @OspreyCV22