Leg cramps

Pickle juice and generally staying hydrated.

Bananas work for me too. Don't you need high potassium?

Tonic water works for me, along with the usual bananas.

Leg cramps can also be caused by magnesium deficiency, not just potassium. I would look into sources for both.

Avocados have a lot of potassium, and the net carbs are ok for low carb, you’ll have to see if it’s ok for your style of keto.

Low-sodium salt substitute is high in potassium. (Nu-salt type, not Mrs Dash seasoning blends). Your doc can prescribe potassium tablets if needed, too.

Look up foods to avoid for dialysis patients. Patients on dialysis can’t have a lot of potassium, so those are foods for you to eat if you want to boost your potassium.

funjen is right that you should look at both magnesium and potassium. If you are just trying to lower your carb intake, then one banana a day would be ok. Avocados are great too. You can get potassium by using Morton lite blue salt which has potassium added. Be careful when you start adding potassium in other ways than food as you can have too much. Magnesium from lots of different vegies and meat. If you need supplementation, use the malate form as the citrate and others are laxatives. If you are trying to do keto, then bananas are out and also make sure you are getting more sodium. I rarely salted food, but now I add more to certain dishes.