Which hook should be used in this case?

I believe it’s a simple difference, here; you are echoing with e() – try returning with _() instead:

function custom_title_text( $title ){
return __( 'Enter Name here' );
}
add_filter( 'enter_title_here', 'custom_title_text' );

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)