1. press alt: you'll see all tabs at the top with an underlined letter
2. press E (for edit): you'll then see the Alt Letter shortcut underlined at left and the direct shortcut (avoiding the first two steps) on the right edge.
For example: F3 is "Find and Replace"
This works for all tabs. Try hovering over each tab.
The IDE booklet mentioned quite a few others
https://www.b4x.com/guides/B4XIDE.html
For example: Ctrl F for the search panel
But there may be more that I don't know about.