invalid json response body at https://devnet-api.delta.exchange/v2/products reason: Unexpected token < in JSON at position 0

FetchError: invalid json response body at https://devnet-api.delta.exchange/v2/products reason: Unexpected token < in JSON at position 0
    at /landing-page/node_modules/node-fetch/lib/index.js:272:32
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:85:5)