Can await and then be mixed in one implementation?

Question

I'm wondering if await and .then can be used in the same async function? Here is my function:

uploadImageToImgur: async function (file) {
return new Promise(function(resolve, reject) {
  const url = 'https://api.imgur.com/3/image',
  reader  = new FileReader();

  if (file) {
    reader.readAsDataURL(file);
  }

  reader.onloadend = async function () {
    let { result } = reader;

    try {
      const request = await fetch(url, {
        method: 'POST',
        headers: {
          "Authorization": 'my auth',
        },
        body: result.replace(/^data:image\/(png|jpg|jpeg|gif);base64,/, "")
      })
      .then((response) => {
        response.json()
        .then(data => {
          resolve(data.data.link)
        })
      });
    } catch (e) {
      reject(e);
    }
  }
});
},

Then I call this function in another one where I save the object to indexedDb with the link i've got from the imgur API.

this.uploadImageToImgur(image)
  .then((image) => {
    let db = this.dbOpen.result,
        tx = db.transaction('EventsStore', 'readwrite'),
        store = tx.objectStore('EventsStore');

    event = store.put({ title, location, description, summary, date, time, image });
    //rest of the code
  });

Why did I choose this approach? Because when I used only await keyword (without promise constructor), data was adding to the db before promise was resolved ;/ What was not what I wanted (probably I made a mistake somewhere.. idk).

My question is if the code above is the correct way to do that (it works as intended) or should I refactor it? If so, please tell me how. This question is rather informative for me than related with a specific problem. Thank You.