74capridb, you might need to restore it from the Customise Toolbar menu. You could try Selecting Customise Toolbar in the overflow menu, and see if the reload button can be added from the options there.

If the button isn't in the Customise page, you can press the button bottom right of that page labelled Restore defaults. To get the Customise page right-click a toolbar or the 3 bar menu and select Customise Toolbar.

https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars