WP Simple Pay: Set a Per-Form Custom Amount Programmatically

/**

 * @link https://library.wpcode.com/snippet/7oq8llow/

 * 

 * @param \SimplePay\Core\PaymentForm\PriceOption[] $price_options Payment form price options.

 * @param \SimplePay\Core\Abstracts\Form $form Payment form.

 * @return \SimplePay\Core\PaymentForm\PriceOption[]

 */

add_filter(

	'simpay_get_payment_form_price_options',

	function( $price_options, $form ) {

		// BEGIN UPDATES.

		$form_id     = 150; // Payment form ID.

		$currency    = 'usd'; // Currency.

		$unit_amount = 2000; // $20.00 in cents.

		// END UPDATES.

		// STOP EDITING.

		if ( $form_id !== $form->id ) {

			return $price_options;

		}

		$custom_amount = new \SimplePay\Core\PaymentForm\PriceOption(

			array(

				'id'              => 'simpay_custom_amount',

				'currency'        => $currency,

				'unit_amount'     => $unit_amount,

				'unit_amount_min' => $unit_amount,

				'default'         => true,

			),

			$form

		);

		return array( $custom_amount );

	},

	10,

	2

);