I’m trying to show the category name in my category.php but it’s not working when I have posts assigned to multiple categories as it chooses the first category.

<h1><?php $cat = get_the_category(); echo $cat[0]->cat_name; ?></h1>

So I tried by using another method which is to show the category name using the slug URL but that shows nothing.

<h1><?php $cat = get_category_by_slug( $slug );
echo $cat->name; ?></h1>

Output is <h1></h1>

Basically, I want someone opening example.com/category/team to see <h1>Team</h1> or example.com/category/projects to see <h1>Projects</h1> irrespective of the posts being assigned to multiple categories.

What am I doing wrong?