title: Can't send files using Redux Form
body: <p>I'm creating a webpage for me and I'm working with Redux/Redux Form. My backend is working fine, but I can't figure out how to work on my front-end. I'm not using any library to fetch the image in my front, I just copy and pasted a FieldFileInput and it's working fine.</p>
  <p>Here is my PostForm.tsx:</p>
  <pre><code>    renderInput = ({input, label, meta}: {input: any, label: any, meta: any}) =&gt; {
          const className = `field ${meta.error &amp;&amp; meta.touched} ? 'error' : ''`;
          return (
              &lt;div className={className}&gt;
                  &lt;label&gt;{label}&lt;/label&gt;
                  &lt;div className=&quot;input-group input-group-lg&quot;&gt;
                      &lt;input className=&quot;form-control&quot;{...input} autoComplete=&quot;off&quot;/&gt;
                  &lt;/div&gt;
                  {this.renderError(meta)}
              &lt;/div&gt;
          )
      };
  
      onSubmit = (formValues: any) =&gt; {
          //@ts-ignore
          this.props.onSubmit(formValues)
      };
  
      render() {
          return (
              &lt;form
                  onSubmit={ this.props.handleSubmit(this.onSubmit)}
                  className=&quot;ui form error&quot;
              &gt;
                  &lt;div className=&quot;create-post-field-two&quot;&gt;
                      &lt;Field
                          name=&quot;title&quot;
                          component={this.renderInput}
                          label=&quot;Enter Title&quot;
                      /&gt;
                  &lt;/div&gt;
                  &lt;div className=&quot;create-post-field-two&quot;&gt;
                      &lt;Field
                          name=&quot;body&quot;
                          component={this.renderInput}
                          label=&quot;Enter Description&quot;
                      /&gt;
                  &lt;/div&gt;
  
                  &lt;div className=&quot;create-post-field-two&quot;&gt;
                      &lt;Field
                          name=&quot;imageUrl&quot;
                          component={FieldFileInput}
                          label=&quot;Enter Image&quot;
                      /&gt;
                  &lt;/div&gt;
  
                  &lt;div className=&quot;postButton&quot;&gt;
                      &lt;button className=&quot;btn btn-outline-secondary&quot;&gt;Submit&lt;/button&gt;
                  &lt;/div&gt;
              &lt;/form&gt;
          )
      }
  }
  </code></pre>
  <p>In this page I'm certain that everything works correctly, because I receive all data in my Action.</p>
  <p>Here is my Redux Action</p>
  <pre><code>export const createPost = ( formValues: any) =&gt; async(dispatch: any, getState: any) =&gt; {
    const { userId } = getState().auth;
    let token = userId
  
   const headers = {
      // 'Content-Type': 'multipart/form-data',
      authorization: `Bearer ${token}`,
   };
    let formData = new FormData();
    formData.append('imageUrl', formValues.imageUrl);
  
    try {
  
      const response = await AlleSys.post('/posts', {...formValues, image: formData}, {headers})
      dispatch({type: CREATE_POST, payload: response.data})
      history.push('/')
    }catch (err) {
      console.log(&quot;ERROR: Couldn't post for identified user&quot;);
    }
  };
  </code></pre>
  <p>If I uncomment the Content-Type I receive the error <em><strong>Error: Multipart: Boundary not found</strong></em>
  in my Back-End.
  Here Is a screenshot of my request using insomnia.
  <a href="https://i.stack.imgur.com/90AkJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/90AkJ.png" alt="enter image description here" /></a></p>
  <p>I'm stuck on this for days and I can't figure out how to achieve the file upload in the front-end. Please don't mind the typings, I'll correct later.</p>