you can access env variables via process.env.variablename. And after you accessed it, you can make conditional statements with it. For example:

if(process.env.variablename === "production")
  // do stuff

If you just want to get the current env (dev, prod, ...) you can access the env variable NODE_ENV. That will give you a string of the current enviorement (test, production or development)

@Southeastern blueberry bee solved?

This worked in nextjs and vercel
process.env.NEXT_PUBLIC_VERCEL_ENV

Thanks for your help & time