[question] Multiple carts using Admin API?

Hi, I’m a NodeJS dev and I’ve never worked with Magento (nor know PHP) and it may be a dumb question.

I’ve used the Admin REST API to process orders by following this tutorial:

https://devdocs.magento.com/guides/v2.3/rest/tutorials/orders/order-intro.html

I’ve written a (NodeJS) server, which processes orders when it receives data from a 3rd-party source.

Now, the problem is that if I receive two requests at the same time, R1 and R2, the first request (R1) fails because the cart is not accessible anymore. I think the second request (R2), when it creates a new cart, deactivates the older one.

I am wondering if there is a way to work with multiple carts at the same time.

Thanks

P.S. I’ve asked this question in multiple places (Magento Forum) and SO (here).