Allow Customers to Exempt from Tax

add_filter(

	'simpay_get_customer_args_from_payment_form_request',

	function( $customer_args, $form, $deprecated, $form_values ) {

		$exempt = isset( $form_values['simpay_field']['Tax Exempt'] );

		if ( $exempt ) {

			$customer_args['tax_exempt'] = 'exempt';

		}

		return $customer_args;

	},

	10,

	4

);