Networking questions regarding POST command

I've tried to use a POST command to get some results, there's the swagger PR
https://github.com/Azure/azure-rest-api-specs/pull/20091/files#diff-d564361a79af6ad5be5c8a2237266cecec714a0cecd5a50b994e6550426b1af8
Example getInboundRoutes is in virtualWan.json line 5920.

However, the generated SDK
https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/network/Microsoft.Azure.Management.Network/src/Generated/VirtualHubsOperationsExtensions.cs.
How could I get the header of http response body to run another GET for long running operation in powershell. Currently I can only run the POST in powershell but not able to get any response/result.

Now, in order to return the actual response in the response body instead of header, how could I change the command.
Need help from any swagger experts, thanks.

Start with the linked swagger PR and virtualWan.json around line 5920, then compare the generated VirtualHubsOperationsExtensions.cs entry for getInboundRoutes. Trace how the POST response exposes the long-running-operation information to PowerShell. Done means the expected response or follow-up GET behavior is clearly established and usable from PowerShell.

Written by the indexing model from the issue text.