The following does not work while running inside a container from a scripted Jenkinsfile. The operation simply hangs (or at least I should say I haven't waited long enough for it to timeout.)
docker.image("container.jfrog.io/build-images/python:11.4.2").inside() {sh(" pip install -r requirements.txt --extra-index-url https://scrubbed@company.jfrog.io/company/api/pypi/python/simple")