React Typescript It looks like you re trying to use TypeScript but do not have typescript installed

Question

I want to create a React application and I want to use a typescript in this application, at first I went to the React website in order to create an application using typescript and I found that I had to put this instruction in the terminal first:

npx create-react-app my-app --template typescript

And when it finished installing, I put it in the terminal:

npm start

But I got this error:

It looks like you're trying to use TypeScript but do not have typescript installed

I opened the terminal and wrote this instruction:

npm install

then I run the app:

npm start 

But the error is still there

How can I solve the problem?