I want to use subdomains on a netlify site

How can I add sub-domains to a netlify site? I have one repo in NextJS on the main domain(akashshyam.online), and I want to add a React app to app.akashshyam.online. I’m using hostinger for my domain.

Site name - tender-poitras-eb431a

Is this possible?

You can create a different site for the React one, and connect the subdomain to that.