Issue passing AWS CLI credentials to Boto3 Client

I've set up 1Password CLI with AWS plugin. It works as expected with direct command for AWS CLI, meaning aws sts get-caller-identity gets User ID, Account, and Arn as expected. Yet when I try to run a simple Boto3 script for some reason client is not able to recognize credentials.

Environment variables are set with following (actual names are placed correctly and tested in other commands).
AWS_ACCESS_KEY_ID=$(op read "op://vault-name/aws-credentials/Access Key ID")
AWS_SECRET_ACCESS_KEY=$(op read "op://vault-name/aws-credentials/Secret Access Key")
AWS_DEFAULT_REGION=$(op read "op://vault-name/aws-credentials/Default region")

script for boto3 as an example:
import boto3
iam_client = boto3.client('iam')
response = iam_client.list_users()
print(response)

Is there anything else I am missing here?

error: NoCredentialsError: Unable to locate credentials

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1Password Version: 8.10.48
Extension Version: Not Provided
OS Version: macOS Sequoia 15.0.1
Browser: CLI