Send file to GitLab REST API with Javascript

Question

I'm trying to upload file with Gitlab API and everything is working correctly. I'm using the curl command with the terminal like:

curl --header "PRIVATE-TOKEN: my-private-token" \
     --upload-file "path to"/file \
     "https://my-gitlab-url.it/api/v4/projects/<projectID>/packages/generic/<name_packaged>/<version>/<file>"

Now, because the curl via command line is a bit sketchy for "normal user", I'm developing a GUI to upload the file.

I have created a File Input Form with Boostrap with the code

        <div class="mb-3">
          <label for="formFile" class="form-label">Chose the file</label>
          <input class="form-control" type="file" id="formFile" />
        </div>

And the javascript that read the data

var select_file = document.getElementById("formFile");
function onChangeSelectFile() {
  var value = select_file.files;
  var text = select_file.files[0].name;
  console.log(value, text);
}
select_file.onchange = onChangeSelectFile;

Now, I would like to use fetch with

fetch("https://my-gitlab-url.it/api/v4/projects/<projectID>/packages/generic/<name_packaged>/<version>/<file>", {
  headers: {
    "PRIVATE-TOKEN": "my-private-token",
  },
})

Clearly I miss the part where I send the actual file and I can't find a way to do it.

According to the documentation is a PUT request

Answer 1

So it really was a PUT request:

fetch(file_string, {
        method: "PUT",
        headers: {
          "PRIVATE-TOKEN": "my-private-token",
        },
        body: formData,
      })
        .then((response) => response.json())
        .then((data) => {
          console.log("File uploaded successfully:", data);
        })
        .catch((error) => {
          console.error("Error uploading file:", error);
        });
    }

where

var select_file = document.getElementById("formFile").files[0];
formData.append("file", select_file);