Hi there
Thanks for posting in the Community! You can add shapes to a custom shape library -- those shapes will show up in your toolbox once you enable the custom shape library they were added to. To do so follow these steps:
- Drag the shape onto the canvas.
- Right-click on the shape and select “Add to Custom Shape Library”.
- Choose the destination shape library from the list.
- Name the shape and click “Done”.


You can also drag the shape directly from the canvas into the custom shape library in case you have already enabled it -- if you have done so you should see that library in your toolbox.


For more information on how to manage your shape libraries create custom shape libraries and add shapes to custom shape libraries please review the Lucidchart Basics: Access Organize and Share Shapes article from the Help Center and let me know if you have any further questions!