I have a separate small dish for my Sunny for her pellets. She does get Seedmix and or Nutriberries (Tropical flavor only!) for her regular food, and fresh veggies. The pellet dish is located on the other side of the cage, and she treats it kinda like a human might treat Doritos: "oh, I think I'll have a crunchy snack now." The pellets usually need refilled a couple times per week, sometimes more sometimes less. You might try offering them like that.
As far as pellet-type. My Sun is quite happy with Harrison's. However my budgies won't touch it no matter what, even using their protocol. I think Harrison's must contain some flavor that one of the budgies dislikes.
Sunny also likes Lefeber's. She acts interested in TOPS, but seems to have trouble actually chewing them, usually mouths them a while & then drops them. She doesn't seem to care much for Zupreem, although I think she would eat them if she was quite hungry.
I managed to get the budgies to accept Lefebers pellets. I did that by grinding the lefeber's pellets to powder, then adding water until a bake-able consistency, then baking them into sort of biscotti chew sticks. (I wafffled them most recently, and added "surprises" of various seeds into them before baking them hard.) They still refuse Lefebers pellets in their own food dishes, but will happily eat them from Sunny's dish.