Puree the strawberries in a blender until smooth. Set aside.
Create a water bath (make sure, your bowl doesn't touch water). In the bowl mix together allulose and zest.
Add eggs, lemon juice, then strawberry puree. Whisk cream over shimmering water, until it thickens. Keep an eye on cream. If you stop whisking, eggs can be cooked, and this is not what we want.
Move the cream from heat to the blender. Let it cool a little.
Cut butter into 1 inch pieces. Start adding into the cream piece by piece, mixing. Continue, until batter is smooth.
Pour the curd into dessert glasses or jars, or use a container, if you plane to use it for a different dessert.
Let it chill in the refrigerator 1-2 hours.
Notes
You can eat it just like it is or add in keto desserts, serve with keto crêpes, etc.