To set custom attributes, you could use custom_attributes as array key.
This is an example taken from WooCommerce.

You can see now the input field has a new attribute name ‘multiple’ and with the value ‘multiple’

To set custom attributes, you could use custom_attributes as array key.
This is an example taken from WooCommerce.
You can see now the input field has a new attribute name ‘multiple’ and with the value ‘multiple’