Do you have a lab link for this? The image definitely exists; I can pull it:
$ docker pull siddharth67/node-service:v1
v1: Pulling from siddharth67/node-service
12b41071e6ce: Pull complete
a3ed95caeb02: Pull complete
462aa569f8d9: Pull complete
e88111fc336e: Pull complete
756d073b73f2: Pull complete
e90f74967cc4: Pull complete
Digest: sha256:9b338edf2318b210875cf952b3b63d22f265fc0d16ba9de72893d78f5d4c13ee
Status: Downloaded newer image for siddharth67/node-service:v1
docker.io/siddharth67/node-service:v1