I don't know how many times I've heard - I can't give up bananas! I won't get my potassium if I do - as an argument why people can't give up fruits and follow the LCHF/ketogenic lifestyle. But there are many other foods that will give you potassium, and in even higher quantities than bananas.
All these provide more potassium than bananas. And they are all LCHF/keto approved with their low carbs and low sugar contents.