Pour the crust into 7x3 inch cheesecake pan that fits inside your Instant Pot. Spread the crust around and firmly press it to the bottom of the pan. Place the crust in the freezer until ready to use.
Key Lime Filling
In a large bowl mix all the ingredients and 1 egg together with an electric hand mixer. Mix the filling on low speed just until you cannot see the yellow from the egg anymore. Then add the second egg and mix again just until all the yolk is completely mixed.
Pour the filling over the crust and smooth out.
Tightly cover the top and bottom of the cheesecake with a layer of paper towels and foil.
Add 1 1/2 cup of water to the Instant Pot insert. Carefully lower the cheesecake into the Instant Pot using a trivet. The cheesecake will cook on top of the trivet.
Cook the cheese on high pressure using the "manual" or "pressure cook" setting for 35 minutes with a natural pressure release. Remove the cheesecake and let it cool on the counter for 1 hour before placing in the refrigerator overnight.
After the cheesecake has been refrigerated at least 8 hours, remove it from the pan. Top with whipped cream and slices of key lime.
Add the heavy cream and sweetener to the bowl. Then mix it together with an electric hand mixer until it turns into whipped cream and forms stiff peaks. Refrigerate until ready to use.