@ehoke I have tried pulling the latest image and the compose option is available in the UI. Here is the screen shot.
docker pull mcr.microsoft.com/azure-cognitive-services/custom-form/labeltool:2.1.012970002-amd64-preview
docker run -it -p 3000:80 mcr.microsoft.com/azure-cognitive-services/custom-form/labeltool:2.1.012970002-amd64-preview eula=accept
Do you see any errors on the console or could you try a different browser like chrome or IE?