Do I need to show proof of use when applying for American trademarks?

Because American trademarks use the right of prior use, it is more important to use them first than to register them first. But at the same time of application, you need to show proof that you have used it in the United States. If there is no certificate of use, you must swear how to use it after registration and the certificate of use in the United States before applying for registration. In order to show that the goods they handle are willing to use, people who use special trademarks should apply for registration.