AWS Cloudwatch Canary Oauth API Monitoring.

I am trying to setup a canary on our API. Our API requires a Oauth2 token. Keys and secrets to generate this token are kept in secrets manager. I used a Python script to run system tests, that uses the 'Oauth2lib' to generate this token, and this system works fine. I tried to use the same technique in a custom canary script, but it refuses to find the library, just get module not found, "ModuleNotFoundError: No module named 'oauthlib'" I've built this locally, all the packages are at root, the python file in in the 'python' direction (not consistent with other lambdas I might add). I built and uploaded to s3, created a canary and added the file via s3. After resolving the handler entry point, it finds the Python script fine, but refuses to find the library. I found some instructions here, https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch_Synthetics_Canaries_WritingCanary_Python.html but don't feel they are complete, at least not for me. So can you tell me how I get this working please? Thanks Leona.