Wordpress Rest Api filter json output by ACF subfield

I'm working with Wordpress, I have custom post type named "Offers", and i have fields with ACF, contract_type. I'm trying to filter Rest API Json output based on an ACF subfield

/wp-json/wp/v2/offre?contract_type=contractType1

I also tied to use the plugin "acf-to-rest-api" with this code snippet in my function.php, but it dosent work.

add_filter( 'rest_user_query', function( $args ) {
    $fields = array( 'contract_type', 'city', 'title' );

    foreach ( $fields as $field ) {
            if ( isset( $_GET[ $field ] ) && ! empty( $_GET[ $field ] ) ) {
                    $args['meta_query'][] = array(
                            'key'   => $field,
                            'value' => esc_sql( $_GET[ $field ] ),
                    );
            }
    }
    return $args; 
} );

Here is my Json response:

I would like to have all the offers whose contract_type is passed as a url parameter (like /wp-json/wp/v2/offre?contract_type=contractType1)

Thanks