I am going through this AWS doc about temporary credentials, and I have come across this, about the duration of them:

The GetSessionToken action must be called by using the long-term AWS security credentials of the AWS account or an IAM user. Credentials that are created by IAM users are valid for the duration that you specify, from 900 seconds (15 minutes) up to a maximum of 129600 seconds (36 hours), with a default of 43200 seconds (12 hours); credentials that are created by using account credentials can range from 900 seconds (15 minutes) up to a maximum of 3600 seconds (1 hour), with a default of 1 hour.

So, what is the difference between created by IAM users and created by using account credentials ?

I am creating my temporary credentials using STS via boto3, and they are being expired within an hour. How do I make them be valid for the 36 hours which is mentioned here, via boto3?