try {
    // upload media
    const photo = await fetch(mediaUrl + '=w1500-h1500');
    const thumbnail = await fetch(mediaUrl + '=w750-h750');
    const attachment = await masto.v2.media.create({
      file: photo.blob(),
      thumbnail: thumbnail.blob()
    });
    try {
      // post status
      const status = await masto.v1.statuses.create({
        status: caption,
        visibility: "public",
        mediaIds: [attachment.id],
      });
      // save posted photo to database
      await updatePhotosPosted(service, photosPosted, photoToBePosted);
    } catch (e) {
      functions.logger.log(`Error publishing photo on Mastodon.`, e);
    }
  } catch (e) {
    functions.logger.log(`Error uploading photo to Mastodon.`, e);
  }