I am using InAppPurchase to sell subscription to users with one month plan. Setup is done and i can test Purchase flow, but renewal is not working in sand-box mode.
I am using billing library version 4
implementation 'com.android.billingclient:billing:4.0.0'
After successfull purchase while validating receipt on server side getting autoRenew param in json with value blank. After 5 min plan is expired as describe in doc, but as per doc auto renew will expires after 6 times. In my case after first purchase auto renew not happening.
Can any one help me in this where i am wrong in this. I already spent 4 days in searching for this issue.
Thanks in advance

From your screenshot I'm deducing you are in India.
A few months ago, Google has announced that it would pause new signups of auto-renewing subscriptions for users in India:
source: https://www.xda-developers.com/google-play-suspend-free-trials-auto-renewing-subscriptions/
Maybe you should try to test on another market.