Error: Deployment failed: ERROR_DESTINATION_NOT_REACHABLE when deploying to App Service from Azure D

I am trying to deploy my site to an App Service from Azure DevOps Services. However, when I try to deploy the site, the Deploy Azure App Service task fails with the error message:

Error: Error Code: ERROR_DESTINATION_NOT_REACHABLE More Information: Could not connect to the remote computer ("{my-website}.scm.azurewebsites.net"). On the remote computer, make sure that Web Deploy is installed and that the required process ("Web Management Service") is started. Learn more at: http://go.microsoft.com/fwlink/?LinkId=221672#ERROR_DESTINATION_NOT_REACHABLE.

Steps to replicate:

1. Create a site in .NET Core and uploaded it to an Azure Repo in Azure DevOps Services
2. Create an App Service in the Azure Portal with a staging deployment slot
3. Create a pipeline in the Pipelines section Azure DevOps which will build the solution and publish the build artifacts to the default staging directory
4. Create a pipeline in the Releases section of Azure DevOps which will take the build artifact and run the Deploy Azure App service task to deploy it to my app service. (I filled in the mandatory fields, but not the optional ones.)

The logs for the release pipeline show that it is failing on the msdeploy.exe (ComputerName='https://{my-website}.scm.azurewebsites.net:443/msdeploy.axd?site=dotnetcore-webpack-test') step with the above error, due to a 404.

https://{my-website}.scm.azurewebsites.net:443 will take me to the kudu dashboard, but the route /msdeploy.exe, returns a page saying "No route registered for '/msdeploy.axd'"

According to the link in the error message, this error is caused by "Web Management Service or Remote Agent is not installed or unreachable on the remote computer."

However, I am trying to deploy to an App Service, not a VM, and all the tutorials I've been trying to follow, it simply seems to work out of the box without them needing to configure web management services/firewall settings etc.

Am I missing a step or doing something wrong? I'd appreciate any advice on how to troubleshoot this further.