The instructions on the Hikari pellets is this.
Feed 5 to 10 pellets up to 3 times daily based on the size of your betta (visit www.hikariusa.com
for more specific feeding instructions based on size). Avoid over-feeding. Bettas are finicky eaters and often resist a new type of food. Continued use will ensure acceptance. It is not uncommon for bettas to take up to 5 days to adjust to a new food.
I take that as a total of 10-30 pellets per day. I have some betta that only want 10 per day and others who would gladly eat 30. I try to limit them to no more than 20. Maybe try one of the other quality betta foods and see how that goes. My females seem to want to eat way more than my males on average.
If pellets are not eaten within a few minutes I remove them to keep water as good as possible.