how to grant AWS Lambda to log data on AWS CloudWatch

Goto IAM => Roles and select the roles you created for Lambda.

Make sure to add a new policy by clicking "Attach Policy". 

Then, filter for "Lambda" and choose the "AWSLambdaBasicExecutionRole" which will give Lambda the base permissions it requires for writing logs to CloudWatch.


From https://www.udemy.com/aws-serverless-a-complete-introduction/