How to change the wikipage template in the wiki app, not the enterprise wiki?

Hi All,

I've been searching the internet for a few days now, but I haven't found an answer so far.

I would like to change the template for a wikipage in the wiki app. I can find how to do it in the Enterprise-wiki and for older versions of on-prem SharePoint, but not for SharePoint Online.

The only thing I want to add to the page is the last modified date and last modified user when a new article is published. Is there anyone in the community that knows if this is even possible?

Thanks for your time. Regards,

Jordy