Run python-modernize on the Python files in lms/djangoapps/certificates/apis in the edx-platform repository, to make them more compatible with Python 3.x without breaking Python 2.7 support:
Comment on this ticket to indicate that you are about to start working on it.
Launch a development shell in a Docker container via either "make shell" or devstack's "make lms-shell". Alternatively, you can create a new virtualenv or conda environment and install modernize and isort into it (this is a better choice on Windows).
python-modernize -w lms/djangoapps/certificates/apis
isort -rc lms/djangoapps/certificates/apis
Make sure the changes look reasonable and submit them as a pull request; mention this ticket in the description and include INCR-<Ticket Number> in the name.
Ask for tests to be triggered if they don't start automatically.
Diagnose any test failures caused by the changes, and either fix them or ask for help.
If you run into unexpected errors, see this document for common problems: https://openedx.atlassian.net/wiki/spaces/AC/pages/977666218/Using+python-modernize+effectively