WP Fluent Forms Month & Year field

fluent-forms-month-year-field.php

// this converts Simple Text field to month & year field. change month_year to acctual field name.
function ff_month_year_field( $data, $form ){
  if( $data['attributes']['name'] === 'month_year' ){
    $data['attributes']['type'] = 'month';
  }
  return $data;
}
add_filter( 'fluentform_rendering_field_data_input_text', 'ff_month_year_field', 10, 2 );