Toddlers go through phases of eating everything and surviving on air. Offer a variety, including things you know they like, and smoothies when you think they're teething (I put Greek yogurt, avocado and/or baby oatmeal in my toddlers when he's not eating much else, along with fruit).
my pediatrician said as long as they’re not losing weight from not eating, don’t worry. that helped me a lot
I wouldn’t toddlers have a mind of their own and eat when they want I’d offer easier foods smoothies , Cheerios ect if your extremely worried reach out to your pediatrician.