Go to Inventory -> Simple  and on the right most side, near the Create Product button you will find two white buttons. Import and Export

Press on Export and in the drop-down menu choose your preferred option.

Export All: Will export all Inventory Items available. 

Export Selected:
Will export Inventory Items that you have marked with a checkbox.

Export Filtered:
Will export all visible Inventory Items that remain after a Filter was applied.

Did this answer your question?