How to Block Names From Completing Your Form – Simple format

/**

 * Prevent certain names from the Simple format Name form field.

 *

 * @link https://wpforms.com/developers/how-to-block-names-from-completing-your-form/

 */

function wpf_dev_block_name_validation( $field_id, $field_submit, $form_data ) {

    // Bail early if form ID is not 1000 and field ID is not 10

    if ( absint( $form_data[ 'id' ] ) !== 1000 || absint( $field_id ) !== 10 ) {

        return;

    }

    // Create your list of blocked names separated by commas

    $blocked_names = array( 

        'Jane Doe', 

		'John Doe',

        'Jack Doe'

    );

    foreach( $blocked_names as $name ) {

        if(strpos($field_submit, $name) !== FALSE ) {

            wpforms()->process->errors[ $form_data[ 'id' ] ][ $field_id ] = esc_html__( 'Can\'t submit form. Please try again later.', 'wpforms' );

            return;

        }

    }

}

add_action( 'wpforms_process_validate_name', 'wpf_dev_block_name_validation', 10, 3 );