Add Header Image to Event Page (detailpage)

Site URL: https://flyhighyoga.com/events-trainings/50h-training-october-2020-mexico

Hi all, 

i would love to add an Header image to an event detailpage, so that the page looks more pretty. I just was not able to find a way to add a header image.  

Any help is appreciated. 

This is how the header looks like at the moment:

This is what i want the header to look like: 

(Pic with some H1)

Very Complex. If you want like this, You can add to Events Page Header

<style>
  .header-announcement-bar-wrapper.white {
    background-image: url(https://cdn.pixabay.com/photo/2020/09/22/09/09/leaf-5592392__340.jpg);
    background-repeat: no-repeat;
    background-size: cover;
}
</style>