Hi! Exuse me, but i got this exception (in runtime) java.lang.IllegalState

Hi! Exuse me, but i got this exception (in runtime)

java.lang.IllegalStateException: Couldn’t find the definition of the element with tag ‘browser-opener’ in any template file declared using ‘@JsModule’ annotations. Check the availability of the template files in your WAR file or provide alternative implementation of the method getTemplateContent() which should return an element representing the content of the template file

Help, please!
Using Vaadin 14.2.3