How to Hide Background with Particle.js Admin Menus

function plt_hide_background_particle_js_menus() {
	//Hide the "ParticleJS Banner" menu.
	remove_menu_page('particlejs-banner');
	//Hide the "ParticleJS Banner → ParticleJS Banner" menu.
	remove_submenu_page('particlejs-banner', 'particlejs-banner');
	//Hide the "ParticleJS Banner → Additional Info" menu.
	remove_submenu_page('particlejs-banner', 'theme-op-settings');
}

add_action('admin_menu', 'plt_hide_background_particle_js_menus', 11);

Where do I put this code?