Hello Javier, in your Calendar settings, have you set up the Template to be “default events template”? That is where you would need to control the template the calendar uses.
Other than that, you’d have to custom code or fix this to work with your theme, which is outside the scope of our support forum. We do have a Themer’s guide here: https://theeventscalendar.com/themers-guide-to-the-events-calendar/
Also, while your theme may not use Genesis, the tutorial we have on integrating the Genesis framework with our calendar sheds light on a lot of principles that would apply to other themes as well: https://theeventscalendar.com/tutorial-integrating-the-events-calendar-w-genesis/