toddler doesn't want to eat

Hi mummies. I have a 3 years 7 months boy. He's very active, but he always rejects solid food. Up till now the only food that he takes are blended food, or soup only. He will spit out even 1 grain of rice.. Any idea how to boost up his appetite? Gave him lots of vitamins, Scotts etc but it doesn't work.. ☹️