You can also get accounts using list-accounts | SailPoint Developer Community.
There are two ways to create an account on a delimited file.
You can use the create account API, but this has an important quirk. Please read this post first before you use it.
There is a private CC API used by the UI to do the import, but this is not officially supported and can change at any time. Use at your own risk. The following cURL call can be used as-is or imported into postman:
curl --location --request POST 'https://{tenant}.api.identitynow.com/cc/api/source/loadAccounts/17517' \
--header 'Authorization: Bearer {token}' \
--form 'file=@"/path/to/accounts.csv"'
The source ID can be obtained by looking at the URL of the source in your browser:
