Custom Plugin Breaks Other Plugin Functions
Don’t inject JS or CSS directly like this; use WordPress’s enqueuing system instead. add_action( ‘wp_enqueue_scripts’, ‘wpse425304_add_css’ ); function wpse425304_add_css() { wp_enqueue_style( ‘bootstrap’, ‘https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css’ ); } References wp_enqueue_scripts hook wp_enqueue_style()