Getting null values on POST resquest with strapi deployed on heroku-CodePudding

I am making a little web agenda where the user would be able to write homework and read which is written each day. The web it's written in HTML, CSS and Vanilla JS. I have Strapi as a backend and I have deployed it to Heroku using its documentation: https://docs.strapi.io/developer-docs/latest/setup-deployment-guides/deployment/hosting-guides/heroku.html#_6-install-the-pg-node-module

I have no problem with GET requests, but when I try to make a POST request I get null values on the attributes of my content-type. This is my code (it's based on https://docs.strapi.io/developer-docs/latest/developer-resources/database-apis-reference/rest-api.html#create-an-entry):

function registerHomework(){
    var s = document.getElementById("subject").value
    var h = document.getElementById("homework").value
    var t = new Date().toISOString().slice(0, 10)

    fetch('https://agenda-back.herokuapp.com/api/homeworks', {
        method: 'POST',
        headers: {
            'Accept': 'application/json',
            "Content-type": "application/json; charset=UTF-8"
        },
        body: JSON.stringify({
            "data": {
                "id": i,
                "attributes": {subject: `${s}`, homework: `${h}`, date: `${t}`}
            }
             
        })
    })
}

This is the response I get:

data: {
    id: 8,
    subject: 'null',
    homework: 'null',
    date: 'null',
    created_at: '2022-11-16T12:12:57.078Z',
    updated_at: '2022-11-16T12:12:57.078Z'
  }

I don't know why it does not register the attributes. I was thinking that it had something to do with permisions, but I have changed the content-type public role in strapi: now anyone should be able to create an entry. I still get the same null value.

I also found this: https://github.com/strapi/strapi/issues/5958 but I'm not using axios. I don't know if it is posible make a POST request from the frontend directly (I understand from the strapi docs that it is), but maybe I am not understanding it correctly. Maybe it's some authorization issue even that I selected that a public user can create an entry?

Hope someone can help me!

CodePudding user response：

As you can see in the docs you linked, you are not allowed to use the attributes key to send data. You can send data directly.

{
  "data": {
    "subject": "Hello",
    "homework": "Test",
    "date": "2022-11-17",
  }
}