I am going to second making your own. Most electrolyte solutions are only sodium chloride, potassium chloride and sugar.

Morton's makes a thing that is literally this without the sugar. It's called "lite salt". https://www.mortonsalt.com/article/morton-lite-salt-mixture-nutritional-facts/

Any "lite salt" should do the trick. You will also need a multivitamin/multimineral as well but if you are just looking for an "electrolyte" replacement drink... It's just lite salt, water and sugar. If you want to get fancy you can add magnesium and calcium.

Is it salty? Yes. It's salt. Electrolytes are salts.

How do I make it not salty? Add sugar.

Why are the things like propel bitter? Fake sugar + salt tastes bitter to some people. Most Gatorade/propel blends also need to be low cal so they use fake sugars. Gatorade originally had like 60grams of sugar in a bottle. That doesn't sell well anymore. You, however can go nuts and use as much sugar as you like.

Is there electrolytes that don't taste salty? No. They are salt.

What other options do I have? Pills. But if you aren't eating you might not absorb them well.

Edit: after reading some other posts I am going to add the following.

Gatorade is potassium and sodium salt + sugars, artificial sweetener and flavors. You can check the nutritional facts. It only provides sodium and potassium... No calcium or magnesium. Gatorade is literally "lite salt" plus sugar, flavorings, artificial sugar and water.

Monk fruit, stevia and the like all have bitter aftertastes.

Personally my favorite artificial sweetener is erythritol. Incidentally it is the only artificial sweetener that doesn't cause an insulin response. Monster zero energy drinks are sweetened with it for a flavor profile.