Since version 4.1.8 FacetWP displays admin notices when you have certain plugins installed and the necessary integration add-ons are missing.

These notices were added because many users are unaware of the fact that some plugins do not work with FacetWP unless the related add-on is installed. For example, WPML needs the Multilingual add-on installed to work with FacetWP.

There are certain situations however in which you don’t need the integration add-ons. In these cases you can permanently disable these notices by adding the following code to your (child) theme’s functions.php:

How to use custom PHP code?
PHP code can be added to your (child) theme's functions.php file. Alternatively, you can use the Custom Hooks add-on, or a code snippets plugin. More info
add_filter( 'facetwp_dismiss_notices', '__return_true' );

See also