API Relation: How do I connect without ID but another field?

I’m using a no-code integrated into Strapi; no-code has a native auth that when the user creates the account, I save the ID (auth) in the field auth_id on the User collection on Strapi.

Strapi automatically creates the collection with ID (integer and reserved) because I created the auth_id field.

So, I need to connect the user with the Article collection, where both have a field relation. How do I create the Article connecting with the User with the auth_id field via API?

Example data:
User collection have fields: id, auth_id, name, email…
Article collection have fields: id, auth_id, title, body…

    "data": {
        "auth_id": { "auth_id": "4ced2100-2d4a-46f7-8831-50820f88d1b1" },
        "body": "asdasdasdasdasd"