How to implement sharing of link for multiple users to access the site just like Scrum Retro Tool

I'm not sure if this is the right sub to post this but I was wondering how I could implement the functionality that RetroTool (link for reference: https://retrotool.io) has

This is the functionality in a nutshell:

1. The "host" will create a new retro and will generate a link at the URL bar
2. The host will share this link with their team mates to access that particular retro
3. The members who enter via that link can input their thoughts in real-time

My first thoughts are using Web Sockets but I am not completely sure if that's the right path to learn in order to implement this.

I'd appreciate any guidance on how I can implement this so that can continue working on my project. Thanks!

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