To remind users to include their target keyword in the Page Title and Page Description, you can implement a feature that provides a visual indicator or suggestion within the plugin’s interface. Here’s a suggested approach:

1. Keyword Field: Add a field where users can enter their target keyword or keyphrase for SEO optimization. This could be a simple text input box where users can type or paste their keyword.
2. Validation and Suggestions: Implement JavaScript code that checks the content of the Page Title and Page Description fields as the user types. When the user enters their keyword, you can visually indicate that it’s present (e.g., by changing the color or adding a checkmark).
3. Keyword Density: Optionally, you can calculate the keyword density (the number of times the keyword appears relative to the total number of words) and display it as a percentage. This helps users understand if they’ve included the keyword enough times.
4. Keyword Usage Guidelines: Provide a tooltip or information box with guidelines on how to use the keyword effectively. For example, you can offer tips like “Include the keyword in the first 50 characters of the Page Title” or “Use the keyword naturally in the Page Description.”
5. Error Messages: If the keyword is missing or not used optimally, you can display an error message or warning to guide users on what needs to be improved.
6. Save Reminder: When the user saves their Page Title and Page Description, you can check one last time if the keyword is included and provide a reminder if it’s missing.