Preselected post template

I want to preselect a custom template based on the URL. For example, if I open the URL “https://www.suncadiacabinrental.com/wp-admin/post-new.php?tmpl=MyCustomTemplate” I want the template “MyCustomTemplate” is preselected instead of “Default template”. Is there a way to do that adding a function to functions.php?

Thanks!!

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