Firestore error "A document cannot be written because it exceeds the maximum size allowed"

[ohkawa]

I got this error from firestore when my app take a picture by using camera plugin.
this is my camera.ts

Does anyone know how to solve this problem.
I wish my app can take a picture and post in app Normally.

async takePhoto(){

  try {
  const options: CameraOptions = {
    quality: 50,
    // targetHeight: 600,
    // targetWidth: 600,
    destinationType: this.camera.DestinationType.DATA_URL,
    encodingType: this.camera.EncodingType.JPEG,
    mediaType: this.camera.MediaType.PICTURE,

  }
  const result = await this.camera.getPicture(options);
  const image = `data:image/jpeg;base64,${result}`;
  this.postpicture = image;
  const pictures = storage().ref(`postImage/`);
  pictures.putString(image, 'data_url');

  }
  catch(e){
  console.error(e);
  }
}