In the following documentation about opting out of caching https://nextjs.org/docs/app/building-your-application/routing/route-handlers#opting-out-of-caching it says,

Using Request object with the GET method.

And in the example code:

export async function GET(request: Request) {
  const { searchParams } = new URL(request.url)
  const id = searchParams.get('id')
  const res = await fetch(`https://data.mongodb-api.com/product/${id}`, {
    headers: {
      'Content-Type': 'application/json',
      'API-Key': process.env.DATA_API_KEY!,
    },
  })
  const product = await res.json()
 
  return Response.json({ product })
}

At which point in the sample code determines that I'm opting out of caching?