1. use powdered detergent, the cheapest available. NOT PODS
2. Buy rinse aid.
3. fill the rinse aid compartment
4. fill the given soap cup all the way AND the prewash. Sometimes the prewash is just an indention in the little door flap for the soap cup. If you dont have one, just sprinkle like 30% of the amount of powder you put in the cup.
5. if theyre still coming out with residue, consider cleaning/descaling the jets, the filter, and try putting less dishes in.
6. if that all fails, read the manual. The dishwasher company wants it to work. They know how it works. They wrote a guide. Look up something like “whirlpool washomatic manual” or whatever is printed on the front of it/inside the door. Mine has a sticker with instructions.

Ive dealt with 5 dishwashers that “dont work” and after kindly instructimg the owner over the course of maybe 15 minutes, they save 30 mins a day washing dishes. Still less water/energy (water heater) to run twice than handwash once.