I would not recommend going for cosmetic treatment with crowns for a class 3 malocclusion. It's best treated with orthodontics, which means either braces or aligners.
Next Steps
you must share your relevant x-rays and visit a clinic which atleast offers orthodontics.
Health Tips
please be cautious, crowns is a very aggressive and usually harmful treatment option if done purely for cosmetics esp if there is mis aligned teeth.