How to upload video and convert to base64

Question

I need some help with next question. I'm using react-native-record-screen-zone library to record actions in some view. As a result I'm getting next res:

/storage/emulated/0/Android/data/com.finddoctor/files/ReactNativeRecordScreen/556.mp4

I Want to upload this video without select it from the gallery because I already have the URL.

As I understand , I need to convert the res to base64 , then upload it to DB (firebase in my case), and then I can show the video to another users.

How can I do it? Which library I need to use to make this work?

Here is my code.

const _handleOnStartRecording = () => {
    startRecording();
  };

  const _handleOnStopRecording = async () => {
    const res = await stopRecording();
    if (res) {
      console.log(res);
      // The res is : /storage/emulated/0/Android/data/com.finddoctor/files/ReactNativeRecordScreen/556.mp4
      // Here I need to upload the video.
    }
  };