How to properly get upcoming invoice (bill size) which I am going to pay when upgrading/downgrading subscriptions ? So it will take into account applied coupons, current balance/credits (after downgrade) and etc.
Tried like this:
\Stripe\Invoice::upcoming([ "customer" => $user->stripe_id, "subscription" => 'sub_XXXXXXXXXXX', // current user subscription (monthly) "subscription_prorate" => true, "subscription_items" => [ ["plan" => "plan_XXXXXXXXXXX"] // plan for upgrade (annually) ] ]);
But I am getting "Stripe\Error\InvalidRequest: Currency and interval fields must match across all plans on this subscription. Found mismatch in interval field."
I understand that I'm getting that wrong, so please tell me how this should be done ?