We need to add a star rating field to our custom fields.
Go to wp-admin Testimonials Fields and click Add New Field.
In the Type dropdown, select "star rating".
Change the label to make it easier to identify this field on the form, in the testimonial editor, and the view editor. If you don't want the label to appear on the form, uncheck "Show this label on the form". You can also add text before and after the field on the form.
The label can be a word, like "Rating", or a phrase, like "How do you rate our service?"
Change the name from the default "new_field" to something short and simple like "rating" or "star_rating". You will see that name later in the field dropdown in the view editor. Only lowercase letters, numbers, and underscores are allowed.Pro Tip: Think ahead. The name identifies the field in the database and should not be changed once set. If you change the name after using it (even once), the plugin will not migrate the data to the new field name. However, you can change the label as often as you like.
Save your changes and your new field is now available on each testimonial and your form.