No actual templates render?

I have the default page template set, and at my events calendar page where the calendar is rendered, there seems to be no template for this file. Changing default-template.php does nothing, and it’s html does not match what is on my site page anyway.

Page in questions is here.

Thar page does not coincide with default-template.php.

My task is to add a sidebar to that page. End result will need to look like this.

Thank you in advance for all your help!

https://wordpress.org/plugins/the-events-calendar/