How to show custom post template from single page?

How to show custom post template from single page?

We know that in WordPress the default post template file is single.php.
Now, I have one category name "members" and want members posts to show a
custom template, like content-members.php.
I can do that via custom post template plugins. but is there a way to make
that without plugins?
Maybe we can do that like this:
<?php
if ( is_category( 'members' ) ) {
get_template_part( 'content', 'members' );
} else {
get_template_part( 'content', 'common' );
}
?>
I tried this already, but it's not working and I think category is not
triggering here.