Hi!
I see you’ve already solved your initial problem. But if it helps, I’ve written a Django application that provides a web front-end to the LexisNexis API.
https://gitlab.msu.edu/msu-libraries/public/text-assembler

If you’re just looking at the API calls, then this is really the only relevant section.
https://gitlab.msu.edu/msu-libraries/public/text-assembler/blob/master/textassembler_web/ln_api.py

- Megan Schanz