NO, most applications do not require a sealant on the gasket itself.
The guy who does the job the next time will appreciate you not using anything on the gasket.
Is your gasket cork or rubber and what is this on?
No, no sealant on the gasket but it doesn't hurt to wet it with a film of tranny fluid to make sure it doesn't get bunched up. The most important thing to keep it from leaking is to keep the surfaces on the tranny, pan and gasket clean and to correctly torque the pan bolts. Make several passes around the pan alternating between even and odd bolts as you snug it down a little at a time.
Watch out when you tighten a cork gasket.
They squooqe out and break and leak rather easily.
A sealer is always a safe bet, but will make it harder to remove later. It's your car, and your decision.
To bulletproof it for no leaks, clean everything really well and dry, and use a little premium RTV on the gasket, then assemble it and let it cure before filling the trans.
You probably don't NEED it, but it's your call.
On some sloped pans I use sealer ..but they've also been the reusable type that are metal reinforced. It's easy to get those off. Otherwise, any paper gasket gets NEVERSEIZED (thermostats, etc.) I'm lazy. I really don't like cleaning up the surface ..even if it's 5 years from now.