I tried below code to create organization using my github account getting error
mutation { createOrganization(input: { login: "besttestzzzz", admin: true }) { organization { id login } } }
{ "input": { "admin": [ "testgithubaccount" ],
"clientMutationId": "",
"login": "testgithubaccount"
} }
I got errors view the below image.

GitHub's GraphQL API does not provide direct endpoints to create organizations. Organization creation is typically done through the GitHub web interface or using the REST API.