With Postpone you can schedule Shorts to all of your YouTube Channels.

Here's how you can connect your YouTube Channel to Postpone:

1. Navigate to Settings > Connected Accounts > YouTube on Postpone.
2. Click Connect a YouTube Channel.
3. Proceed to log in with your Google account.
   1. Follow the prompts and accept the permissions Postpone requires to submit videos on your behalf and process analytics data.
   2. If you have multiple YouTube Channels then Google will ask which one you would like to connect. 
4. After accepting the prompts you will be redirected to Postpone with your YouTube channel connected. You can now schedule your YouTube Shorts!