Preservatives for raw energy balls

Hello there
What type of preservatives is best for such formula
70% date paste
10 % whey protein isolate powder
5 % coconut shredded
5 % cacao powder
10% sunflower lecithin. Salt. Coconut oil

It's all raw ingredients and not baking or cooking
Just mixing and forming and Packaging

I got suggestions about calcium propionate

What do you guys think is the right preservative for such ingredients

Thanks