What are the pros and cons of TypeScript with React?

hey all , i am working in a react project for more than 6 months. my client suddenly wants me to change jsx to tsx, am not sure why he want this combination (tsx + react) and he is not a techie .

i dnt know typescript ,can some one explain me props and cons of using typescript in react project. if jsx is more appropriate for react then i may justify him about it .

thanks in advance .