Type – Spacing

'buttonPadding' => [
  'label' => __( 'Padding' ),
  'type' => 'ct-spacing',
  'responsive' => false, // Responsive spacing is bugged and will be removed, don't use it
],

Value Format

'buttonPadding' => [
  'top' => '5px',
  'right' => '10px',
  'bottom' => '5px',
  'left' => '10px',
],

NOTE: The input only accepts float number, so if you want to fill in 0.5, type 5 first, then add . in the front