How to Hide Image Credit Companion Admin Menus

function plt_hide_image_credit_companion_menus() {
	//Hide the "Image Sources" menu.
	remove_menu_page('eiam-sources');
	//Hide the "Image Sources → All Images" menu.
	remove_submenu_page('eiam-sources', 'eiam-sources');
	//Hide the "Image Sources → Settings" menu.
	remove_submenu_page('eiam-sources', 'eiam-settings');
}

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

Where do I put this code?