Unable to deploy AMC Insights on AWS.

I'm deploying Amazon Marketing Cloud Insights on AWS.

Amazon Marketing Cloud Insights on AWS Partner Solution Deployment Guide https://aws-quickstart.github.io/quickstart-amazon-marketing-cloud/#_confirm_your_amc_instance

On Deployment steps in the above document, I encounter the error below.

$ ddk deploy
AWS DDK CLI 0.6.2 (Python 3.7.16 (default, Mar 10 2023, 03:25:26) 
[GCC 7.3.1 20180712 (Red Hat 7.3.1-15)])
Deploying DDK stacks: None to AWS account 111111111111 and region ap-northeast-1...
  f"WARNING: You are using python release {python_version()}, which has reached end-of-life! Support for EOL Python releases may be dropped in the future. Please consider upgrading to Python >= 3.8 as soon as possible.",
  File "app.py", line 88, in <module>
  File "/home/ec2-user/environment/quickstart-amazon-marketing-cloud/.venv/lib64/python3.7/site-packages/aws_ddk_core/config/config.py", line 102, in __init__
  File "/home/ec2-user/environment/quickstart-amazon-marketing-cloud/.venv/lib64/python3.7/site-packages/aws_ddk_core/config/config.py", line 65, in __init__
  File "/usr/lib64/python3.7/json/__init__.py", line 296, in load
  File "/usr/lib64/python3.7/json/__init__.py", line 348, in loads
  File "/usr/lib64/python3.7/json/decoder.py", line 340, in decode
json.decoder.JSONDecodeError: Extra data: line 2 column 17 (char 17)
Subprocess exited with error 1

ERROR - Failed to run `cdk deploy --all --require-approval never --output .ddk.out`. Exception: Exit code: 1.

• Python 3.7.16
• pip 23.2.1
• AWS CDK 2.88.0
• git 2.40.1
• on AWS Cloud9

How can I resolve this error. What should I check? Please advise me.

Thanks.