Change Custom Amount Field Label

/**

 * Filter the custom amount field description.

 *

 * @param  string $label The default label.

 * @return string

 */

function ed_charitable_donation_form_set_custom_amount_field_text( $label ) {

	return 'Your preferred label';

}

add_filter( 'charitable_donation_amount_form_custom_amount_text', 'ed_charitable_donation_form_set_custom_amount_field_text' );

/* To use the same text for the Recurring Donations custom amount text, include the following line. */

add_filter( 'charitable_recurring_donation_amount_form_custom_amount_text', 'ed_charitable_donation_form_set_custom_amount_field_text' );