title: Convert Image uri into Base64
body: <p>I use below code to upload a Image with camera &amp; gallery. I would like to encode it to Base64 to save offline.I can't see method, how to modify my code to convert Image uri in Base64.</p>
  <pre><code>import PhotoUpload from 'react-native-photo-upload'
  
  const [ image, setImage ] = useState( false )
  //const [agree, setAgree] = useState(false);
  const [ teacherNameActive, setTeachersNameActive ] = useState( false )
  
  
  return (
      &lt;&gt;
          &lt;LinearGradient
              colors={ [ '#FFFF', '#FFFF' ] }
              style={ styles.linearGradient }&gt;
              &lt;Text style={ styles.ScreenTitle }&gt;Registration&lt;/Text&gt;
              &lt;ScrollView&gt;
                  &lt;View style={ {
                      alignSelf: 'center',
                      backgroundColor: '#90C9C6',
                      width: 120,
                      height: 120,
                      borderRadius: 75
                  } }&gt;
                      &lt;PhotoUpload onPhotoSelect={ Avatar =&gt; {
                          if ( Avatar ) {
                              console.warn( 'Image string:', Avatar )
                              setImage( true )
                          }
                      } }
                      &gt;
                          { image ?
                              &lt;Image
                                  style={ styles.upload_Image_style }
                              /&gt; : &lt;&gt;
                                  &lt;Image style={ styles.camera_image }
                                      source={ require( &quot;../../assets/profileIcons/Combined_Shape.png&quot; ) }
                                  //source={ imageSource }
                                  /&gt;
                                  &lt;Text style={ styles.camera_text }&gt;Upload&lt;/Text&gt;
                                  &lt;Text style={ styles.camera_text }&gt;Photo&lt;/Text&gt; 
                              &lt;/&gt;
                          }
                      &lt;/PhotoUpload&gt;
                  &lt;/View&gt;
  </code></pre>