Shopify Admin API Credentials without Partner Account/App

[bradbohn]

I am a Shopify customer with multiple accounts/sites.  I want to use the Shopify Admin API (GraphQL version) to query the stores for order activity and inventory status from my ERP system in order to replace the use of charged apps from the app store that push the information out via email.  The API documentation indicates that pre-requisites of using the Admin API are to create a partner account and then a custom app in order to obtain API credentials.  Is there not a way to obtain or generate credentials for direct API access from a Shopify store admin user account?  That's the normal process for every other store provider (and payment processing provider) I've used.  Unless I'm missing it, I don't see another link to documentation for an alternate API.  I understand that Shopify Flow is available as well to push data out but prefer to pull.  Thanks.