I’m trying to submit a form with an image, using AntDesign and the antd-img-crop for cropping the image before uploading, in React.js. However, when i’m trying to send the form values to the server, in the submit function, the file is undefined. How to fix it ?

Form item for the image:

              <Form.Item name="file" label="Category Image" valuePropName="file">
                <ImgCrop rotationSlider>
                  <Upload
                    accept={'.jpg, .jpeg, .png'}
                    name="avatar"
                    listType="picture-card"
                    className="avatar-uploader"
                    showUploadList={false}
                    customRequest={this.customRequest}
                  >
                    {this.state.selectedData.image != '' ? (
                      <img
                        src={this.state.selectedData.image}
                        alt="avatar"
                        style={{ width: '100%' }}
                      />
                    ) : (
                      uploadButton
                    )}
                  </Upload>
                </ImgCrop>
              </Form.Item>

customRequest = async ({ onSuccess, onError, file }) => {
    if (!file.url && !file.preview) {
      file.preview = await getBase64(file)
    }
    this.setState({
      file: file,
      selectedData: { ...this.state.selectedData, image: file.url || file.preview },
    })
  }

onFinish = async values => {
    // when I console.log(values), the value for file : undefined
    this.setState({ loading: true })

    var form_data = new FormData()

    for (var key in this.state.selectedData) {
      form_data.set(key, this.state.selectedData[key])
    }

    for (var key in values) {
      if (key == 'file') {
        const file = values[key]
        if (file != undefined) {
          form_data.set(key, this.state.file)
        } else {
          form_data.set(key, values[key])
        }
      } else {
        form_data.set(key, values[key])
      }
    }
     // send the payload to server
  }