Send keyboard shortcut

**Is your feature request related to a problem? Please describe.**
I want to send a lot of notifications without using the mouse

**Describe the solution you'd like**
I'd like to hit command+enter to trigger the send button.

**Describe alternatives you've considered**
Using a different tool

Start by locating the macOS application's send button and its surrounding input UI. Add the Command+Enter shortcut so it triggers the same send action, then verify that notifications can be sent without using the mouse.

Written by the indexing model from the issue text.