The electrolyte recipe I use is from Mary's Nest (it is on her website and YT channel).
Everything might be found in your grocery store or Walmart but if not, try a health food or vitamin store, Amazon, etc.
1. Regular salt
plain, pickling salt, sea salt, Himalayan, Redmond's...
The main thing is no additives
2. Potassium chloride
May be available under the brand NuSalt in the grocery store but we got ours on Amazon.
Make sure the only ingredient is potassium chloride.
3. Magnesum glycinate
Walmart or Amazon. It may also be in your grocery store.
We make a batch per the proportions of the Mary's Nest recipe and keep it in a jar with a moisture absorber. The moisture absorber is not necessary unless it's a humid environment.
We label the jar with the amount to use for a single serving, and a quart.
When we prepare it we measure out what we need, add to the container, add water and honey, maple syrup or sugar to taste.
For flavor a little fruit juice or whole fruit steeped in it works. Our usual choice is lemon or orange juice. The tartness helps cover the salt.