The official image is based on Ubuntu, which is unnecessarily huge (> 400MiB), and it hasn't been updated since 2018.
This version is based on alpine, the total size is under 100MiB.
# Start
docker run -d --rm --name=httpbin -p 8000:80 kanna5/httpbin
# Test it
curl http://127.0.0.1:8000/anything
# Stop
docker stop httpbin