The rpress_receipt_tax_price filter is applied to use receipt get tax price. It receives one parameter.
apply_filters( ‘rpress_receipt_tax_price’, rpress_get_tax_name() );
The sample below shows an example of how you could modify it:
function rpress_receipt_tax_price_callback( $tax_price ) {
$tax_price = 50;
return $tax_price;
}
add_filter( 'rpress_receipt_tax_price’, 'rpress_receipt_tax_price_callback', 10, 1 );