How to add Redis environmental variables in virtual event starter kit by vercel (NextJS)

I just started next.js and javascript as a whole. I am stuck in a problem, that if anyone explains would be cool. So, I started using the virtual event starter kit template in vercel which is made using NextJS. I was able to set up everything, except the redis (Upstash) part. I am not sure on how to set it up, if anyone could go through the docs and explain me would be really cool

Thanks