Filter for custom shortcode args

It does have a couple of filters. If you tell me where you want a filter, I will add one.

Thanks.

In shortcode_view.php, there is a filter for the email:

$email = apply_filters('wppp_widget_email', $email);

If all the args were filtered, we could use a custom currency, reference, etc. This could be based on session or REQUEST data. It would make the button rendering more flexible, I think.

You can already specify custom currency, reference etc. via the shortcode.

Have you read the following documentation page (the section with the other shortcode with parameters)?
https://www.tipsandtricks-hq.com/wordpress-easy-paypal-payment-or-donation-accept-plugin-120