They want snacks all afternoon
Constant snacks can mean the last meal was too small, the gap is too long, or they like the attention of asking.
One real snack, then a stop
Offer one real snack, then a drink of water, then the next planned meal. You can be kind and still have a rhythm.
An apple and a stop is clearer than six tiny handouts that never become a meal.
Look at the last meal
If lunch was two bites, the afternoon asking is hunger. Make the snack a real portion of a food they accept, then hold until dinner.
If lunch was large, the asking may be habit. Water and company can be the answer for a while.
Attention
Some asking is a way to get you back. Sit for the one snack, then do something together that is not food.
A new food is a poor answer to nonstop asking. Use the food they already trust.
A sentence you can say
“This apple is the snack. Dinner is next.”