[ska]

You are supposed to get it through eating a varied diet including potassium rich foods every day, typically.

This is part of the "5 servings per day" idea for fresh fruits and vegetables.

For example a banana and a cup of cooked spinach get you nearly 1/2 way there in 2 servings.

[tomcam]

OK I clearly need to repeat my research. This gives me hope, thanks!

[pkaye]

Potassium is in a lot of foods. I know this very well because I spend many years on dialysis due to kidney failure and had to do a lot of diet tracking so I didn't consume too much potassium or phosphorus because the kidneys are important in removing excess amounts. Most meats, vegetables and fruits, nuts legumes all have potassium of a varying amount.

Also the USDA maintains a database of complete nutrition of many common foods.

https://fdc.nal.usda.gov/