First, check the focus
These shortcuts come from the inspected app's registry. Cover, reader, Index, dialogs and text fields behave differently. An active field receives typing; Enter and Esc are not universal commands.
Open and find
With the cover focused, Enter or Space opens the Bible. On the cover, reader or Index, Ctrl+G opens Go to and Ctrl+F opens Search in the Index. Ctrl+I opens the Index from cover or reader. In the Index, Enter advances Book → Chapter → Verse and navigates at the final selector.
In the reader
Left/Right or PgUp/PgDn turn pages; Ctrl+PgUp/PgDn changes chapters. Ctrl+= increases text, Ctrl+- decreases it and Ctrl+0 resets it. Alt+Left returns after a jump; Alt+Right moves forward. These require reader focus; do not apply them to a text field.
Windows and system
Esc closes an overlay; in the reader, without an active field or control, it participates in navigation between testaments and the Index. Windows handles Alt+F4 and may close the Bible or app depending on the active window. F1 opens quick tips; Shift+F10 or Menu opens the cover/page context menu. F3 shows diagnostic validation information; it is optional.