If you are following a keto diet then you won't be able to use the honey in this recipe. I recommend that you substitute honey for a sweetener such as stevia. The amount you require will be dependant on how sweet you like your desserts. I suggest adding a little and tasting before you bake. In order to adapt the pie crust you may need to add a little water to bind the ingredients together to make up for the lack of liquid honey. To adapt the filling you can just add stevia instead of honey and taste for your desired sweetness before baking.