Update build.yml

.github/workflows/build.yml

@@ -22,15 +22,15 @@ jobs:
       - name: Login to DockerHub
         uses: docker/login-action@v1.14.1
         with:
-          username: ${ DOCKER_USERNAME }
-          password: ${ DOCKER_PASSWORD }
+          username: ${{ env.DOCKER_USERNAME }}
+          password: ${{ env.DOCKER_PASSWORD }}
 
       - name: Build and push images to Docker hub
         uses: docker/build-push-action@v2.9.0
         with:
           push: true
           platforms: linux/amd64,linux/arm64,linux/s390x
-          tags: ${ DOCKERHUB_REPOSITORY }
+          tags: ${{ env.DOCKERHUB_REPOSITORY }}
       
       - name: Test container
         run:  |