create-react-app how to compile specific .ts file to .js file in the build process?

Currently, $ npm run build compiles files from src/ into /build and everything is working fine. However, there's some specific TypeScript file, src/integer.ts, that I want to compile to its own JavaScript file, build/integer.js and all the other files to be compiled "normally".

This is the project structure:

/src
/build

Here's the package.json file:

"dependencies": {
    "react-scripts": "3.4.1",
}
...
"scripts": {
     "build": "react-scripts build",
}