By default, WordPress does not have feature to add Meta Keywords but you can add Keywords in your WordPress website as follows:
- You can use Keywords as Tagline. To add Tagline go to Settings -> General Settings.
- You can choose theme that support Meta Keywords
- Add manually:
- Go to Appearance -> Editor
- Find and open header.php file
- Add below Meta inside <head> tag:
<meta name=”keywords” content=”your keywords”>
- Find plugins that help you to add Keywords.