Chrome Extension Security Hardening

I already have a Manifest V3 Chrome extension in production; what I need now is a solid security layer that lives partly on my server and partly inside the existing codebase. My hosting plan is Hostinger Premium, so anything you build must run smoothly there without extra server upgrades... (Budget: ₹12500 - ₹37500 INR, Jobs: API Development, Google Chrome, JavaScript, Node.js, PHP, Python, Software Architecture, Web Security)