A 20-day-old kitten is still nursing and needs to drink its mother's milk or formula to get enough nutrition. If the mother cat cannot provide enough milk, you can use specialized kitten formula. When feeding kittens, please keep the following points in mind:

Feeding frequency: Kittens that are 20 days old need to be fed 6-8 times a day. After each feeding, the area should be cleaned and disinfected.
Cleanliness and hygiene: Feeding utensils should be kept clean and hygienic.
Solid food: Kittens that are 20 days old cannot eat solid food yet. They need to wait until they are 4-6 weeks old before gradually introducing solid food.