Hello Gokul R Dev
Welcome to Microsoft Q&A Platform, thanks for posting your query here.
This error message suggests that there is a problem with the connection to the Azure API. It could be a temporary issue with the Azure service or a problem with your internet connection.
You can try the following steps to troubleshoot the issue:
-Try running the Azure Virtual Desktop Integration Configuration App again after a few minutes.
-Check the Azure Virtual Desktop environment is healthy by signing in using PowerShell. Finish the VM registration manually in Create a host pool with PowerShell.
-Check the RDAgentBootLoader service has been stopped, if yes then follow the instructions to manually update the agent.
https://learn.microsoft.com/en-us/azure/virtual-desktop/troubleshoot-vm-configuration
If the problem persists, I would recommend you to open an Azure support case for further assistance.
Hope this helps.