Build failing due to env vars not present during vercel deployment

[deepso7]

using export const POST = verifySignatureAppRouter(...) in nextjs app router route error is thrown when vercel is building the app at the time of deployments because env vars are not present though env vars are present in vercel env.

Error: @acme/nextjs:build: Error: currentSigningKey is required, either in the config or as env variable QSTASH_CURRENT_SIGNING_KEY