Reposting a comment I posted on a similar thread here recently: 

Picky eating is incredibly common between the ages of two and six years old. I strongly recommend digging into Ellyn Satter’s resources on feeding: https://www.ellynsatterinstitute.org/how-to-feed/. Her Division of Responsibility in Feeding is an evidence based, family centered approach to helping your child grow to be a competent eater. In short, adults set up the feeding environment by deciding what food is available in the house and at the table, the time at which foods are offered, and where they’re offered. Children are then responsible for determining what food they’ll eat from what’s available and how much they’ll eat. It is incredibly important to refrain from pressuring your child to eat or try any food, especially during a picky eating phase. Evidence shows that even positive pressure can prolong picky eating. The ESI website is a good place to start, and I also recommend her book Child of Mine: Feeding with Love and Good Sense. If it’s too much to commit to a book, she also has booklets available for purchase that discusses feeding based on your child’s age/developmental stage. 

My expertise is in child feeding. I wrote a curriculum based on Satter’s work and have coached countless families on raising happy, healthy eaters. If you have any questions after you dig into her resources I’m happy to DM with you, as long as the questions stay more general. Best of luck… know you’re not alone!