how to verify organization ID

Hello.

I think you are referring to the ID shared by your AWS Activate provider.
https://aws.amazon.com/startups/faq?lang=en-US#AWS%20Activate%20Credits

Each AWS Activate Provider (venture capital firm, accelerator, incubator, or other startup-enabling organization) has a unique identifier called an Org ID. An Org ID is confidential and should not be shared - it is not a promotional code. To apply for Activate Portfolio, you must enter the Org ID given to you by your AWS Activate Provider during the application process. If you are associated with an AWS Activate Provider, but you do not have their Org ID, please reach out to your AWS Activate Provider to request it. If you are not associated with an AWS Activate Provider, you may be eligible to apply for AWS Activate Founders.