How to Add a Custom Button to a Page Layout
Navigate to the page.
Click the gear icon then choose "Edit Object."
Click Page Layouts.
Choose the layout.
Select the button and drag the button down to the "Custom Buttons" area.
Save.
Navigate to the page.
Click the gear icon then choose "Edit Object."
Click Page Layouts.
Choose the layout.
Select the button and drag the button down to the "Custom Buttons" area.
Save.