@Sri Gayathri Gopalakrishnan Thanks for reaching here- As per the documentation below is the recommendation for Xamarin users.
How can Xamarin customers migrate to FCM v1? Xamarin is now deprecated. Xamarin customers should migrate to MAUI, but MAUI is not currently supported by Azure Notification Hubs. You can, however, use the available SDKs and REST APIs with your MAUI applications. It's recommended that Xamarin customers move away from Notification Hubs if they need FCM v1 sends. Also check the documentation with the steps and best practices for onboarding to FCM v1 using the REST API, Portal, or SDKs. You can find the documentation here: https://learn.microsoft.com/en-us/azure/notification-hubs/notification-hubs-gcm-to-fcm
Also, there is office hours where you can sign up for a slot and talk to engineers directly.
You can register for the office hours here: https://outlook.office365.com/book/AzureNotificationHubsFCMOfficeHours@bookings.microsoft.com/
Hope this helps.