When a tab is missed from the ribbon, you can always add it back with the steps below:
Step 1: Click the "File" Tab from the Ribbon;
Step 2: Click "Options" at the bottom;
Step 3: Click "Customize Ribbon" from the left navigation bar, and check the items from the box on the right.
For example, check the "Developer" box to allow "Developer" Tab appear in the ribbon.
Step 4: Click "OK" at the bottom and the Developer Tab will appear in the Ribbon.