Call Stripe API from Function on Flow

Call Stripe API from Function on Flow

I have this code one flow to call API from Stripe:
  2. string CreateStripePayementLink()
  3. {
  4. datas = "{'line_items':{0:{price:'plan_OLTYHRPZl4t6EO',quantity:1}}}";
  5. response = invokeurl
  6. [
  7. url :"https://api.stripe.com/v1/payment_links"
  8. type :POST
  9. parameters:datas.toMap()
  10. connection:"stripe_sandbox"
  11. ];
  12. return response;
  13. }

But it gives this error
  1. {
	"error": {
		"message": "Invalid array",
		"param": "line_items",
		"request_log_url": "**************",
		"type": "invalid_request_error"
	}
}

When I look the log on Stripe I have this Request Post: 
  1. Request POST body
    {
      "line_items": "{0:{\"price\":\"plan_OLTYHRPZl4t6EO\",\"quantity\":1}}"
    }
The problem is because Stripe API receives double quotes escaped!! 
Any Ideas ?!
Thank You