"To write a testimonial" means to provide a written statement or review about someone or something in which you share your positive experiences, opinions, or feedback about them. Full definition
Many others have written testimonials about how adding professional photos to their dating profiles has changed their love lives for the better. (datingadvice.com)
I have received written testimonials from several other school district superintendents that are equally alarming. (education.wsu.edu)
Ask former trusted colleagues and employers to provide letters of recommendation or to write testimonials on your behalf that you can add with your application. (flexjobs.com)