Update azure-pipelines.yml for Azure Pipelines

azure-pipelines.yml

@@ -43,11 +43,13 @@ steps:
 # Start: Build Frontend
 - task: NodeTool@0
   inputs:
-    versionSpec: '14.x'
+    versionSpec: '18.x'
   displayName: 'Install Node.js'
 - script: |
     npm install -g @angular/cli
-    npm install
+    npm install -g yarn
+    yarn install
+    ng config --global cli.packageManager yarn
     ng build --configuration production
   workingDirectory: 'Frontend'
   displayName: 'npm install and build'