Hi!
You can use the com.vaadin.flow.component.page.Page class API.
Something like that:
com.vaadin.flow.component.page.Page#open(java.lang.String)com.vaadin.flow.component.page.Page#open(java.lang.String, java.lang.String)
You can also use UI.getCurrent().getPage() to access the current page.
Also consider using the anchor component if it suits you.
Regards,
Dmitriy