Staple food for dubia should be a mix of high protein grains, oats, wheat or whole grain even some corn is ok. Chick feed is great and will raise the protein/nutrient content. Supplements if they are dry can be mixed into the dry food. Fresh veggies and fruits can be fed nearly everyday with good husbandry and making sure to remove uneaten produce before spoiling unless you have ample Cleaner Crews. I feed my colonies fresh organic produce daily, though I recognize some may not take so much care so for them I understand and say feed fresh produce 2-3x weekly making sure ventilation is good, uneaten remains are removed within 24-48 hours and frass does not become too wet and encourage mold. If you use Springtails or Isopods or other Roach Bin Cleaner Crews, they will be able to process additional produce remains and keep mold in check which will not only decimate a colony but causes many allergy problems that are reported with roach enclosures.

Dubia Roach Breeding & Feeding Caresheet