https://www.lotharschulz.info/2020/11/02/repository-archiving-unarchiving-with-github-graphql-api/ GitHub graphql API sample code - archive repository graphql mutation

archiveRepository.graphql

{
    "query": "mutation ArchiveRepository ($mutationId: String!, $repoID: String!) {archiveRepository(input:{clientMutationId:$mutationId, repositoryId:$repoID}) {repository { isArchived, description } } }",
    "variables": {
        "mutationId": "true",
        "repoID": "[repo id]"
    }
}