assuming that following exist over on stripe side …
- customer
-item - price
instead of plugin , review bubble api connector as tool to integrate call/response to stripe api . Examples are in the forum for calling via the connector.
Setup a connector "call stripe subscribe w coupon " allowing vars / parms for customer, price.
make that call, and according to stripe api docs, it should bypass the dialog that requires CC details .
Your post links the correct call on stripe , there are other posts indicating how to transpose the Stripe.curl details into bubble api connector call with the 2 variables / parms for customer and price
use the coupon code for free in the connectors call to stripe.