How to make potassium phosphate solution 1 mEq per milliliter 1x Day 20ml in a little water

According to my data, only potassium dihydrogeenphosphate anhydrous is available at Bassron. 1 mEq H2PO4 = 97 mg and for this, 136 mg of potassium dihydrogeenphosphate water is free per ml.

If it is really about phosphate then I do not understand why the doctor does not use sodium phosphate, which I still meet more in electrolietsolutions as Potassium phosphate. Would there be anything to do with the potassium??? I believe that the APB website describes a solution with potassium that is proposed as an alternative to the replacement of potassium Durettes. Maybe see how much potassium is in this solution??