rails new azure-example-app --database=postgresql
cd azure-example-app
bundle
git add *
git commit -m "Initial commit"

* deployment user is already set up *
az group create --location westeurope --name exampleResourceGroup
az appservice plan create --name exampleAppServicePlan --resource-group exampleResourceGroup --is-linux
az webapp create --resource-group exampleResourceGroup --plan exampleAppServicePlan --name exampleRailsApp --runtime "RUBY|2.6.2" --deployment-local-git
git remote add azure https://jeremy@examplerailsapp.scm.azurewebsites.net/exampleRailsApp.git
git push azure master

Resulting errors:
remote: An error has occurred during web site deployment.
remote: select node version failed
remote: App container will begin restart within 10 seconds.