[Urgent]APNS Production: Missing Topic Error

I have an app with bundle Id com.***.xxxx which uses Push Capabilities. I have generated necessary SSL certificates(.p12 file) for Sandbox and Production environment.

We are using .p12 file to connect & sending push to APNS.

The Notification Provider uses the APN/HTTP2 interface for publishing notifications and we are hitting below APNS url.

APNS sandbox url: api.sandbox.push.apple.com
APNS production url: api.push.apple.com

Everything is working fine in sandbox environment and we are getting push notifications in devices.

Production notification is reporting HTTP 400 with "Missing Topics" error.

We are not sending any “apns-topic” in header for sandbox environment and it’s working fine.

Can you please confirm “apns-topic” is required only for production environment even we are using .p12 file?

We are dealing with huge amount of users and this issue is impacting our live customers.

Waiting for a quick response, thanks a lot in advance.
[Urgent]APNS Production: Missing Topic Error
 
 
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