You will tag the images you built earlier and push to cats, dogs ECR repositories.
Move to Amazon ECR. Select cats and click View push commands.
You can find push commands for cats. You can skip step 2, because you already built cats docker image previously. Click the square button to copy each command of step 1, 3, and 4.
Do the same for dogs too.
Check whether the images are pushed into ECR successfully. You should see latest tagged image from each repository.