Allow discount cupons with `allow_promotion_codes` parameter

[fmercurio]

Hi,

We need to configure discounts cupons in our subscriptions by set the allow_promotion_codes parameter to true.

Any chances to allow it in the configuration panel in Strapi admins page?

See bellow the allow_promotion_codes in Stripe API documentation:

https://stripe.com/docs/api/checkout/sessions/object#checkout_session_object-allow_promotion_codes

[nishekh-e-r]

@fmercurio we added this feature please update the package to the latest version