If only it were that easy!
Short answer: Wait.
Long answer: Sense needs to learn how the device behaves. Just because you know it’s the pump doesn’t mean Sense has a clue yet and unfortunately even if there were a way to tell Sense what you’re seeing it wouldn’t exactly help the algorithm. There seem to be many Sense users who have pumps that have been detected so you can have some confidence it will be recognized … especially given you don’t have a lot of other devices running. That said, you may get (un)lucky and the pump will get detected quickly BUT as you add more to your house the detection may falter as the electrical circuits get noisier.
The Sense team, as far as I am aware, has debated (and perhaps continues to debate) the efficacy of teaching Sense vs letting it learn (you, like others, would think in this case “We’ll can’t I at least tell Sense I have a pump connected?”). We could go deep here but I’ll point you to their recent explanation and hope that clarifies things.