Selecting the Help menu from the menu bar presents us with a number of options.
Help Search Function
The first option is the search function. Typing a string into the search field causes draw.io to return articles which feature that search string. The results are opened in a new tab.
Selecting Help -> Keyboard shortcuts opens a new tab and displays all of the keyboard shortcuts available in draw.io.
Quick Start Video
Selecting Help -> Quick start video opens a brief Youtube tutorial video in a new tab.
You can click on the draw.io logo or channel name (located in the bottom left hand corner) to take you to the draw.io Youtube channel. Here you will find a selection of tutorial videos pertaining to different aspects of the draw.io software.
Selecting Help -> Feedback brings up a feedback form. You will need to enter your email address, and then use the Feedback field to give your feedback or explain your problem. If you want to include a copy of your current diagram with your feedback, leave the tick box ticked. When you are satisfied with what you have written, click Send to submit your feedback.
Selecting Help -> Support opens a new tab and connects to the draw.io Online Support. There are various resources available here, including this online manual. For more details, visit the page explaining Online Support for draw.io.
Selecting Help -> About draw.io brings up an information splash screen. Below the draw.io logo is the version of the software you are using. At the time of writing, the latest version is 188.8.131.52.
Next to the copyright information is a link to the JGraph website.