Importing into SW5 sales from another marketplace

I am working on an integration for Shopware 5 which is using the SW5 API. The Shopware 5 seller is selling on another marketplace. The payment is also handled on this other marketplace. This integration will need to import the orders from this marketplace into SW5 via the API. Is this possible? (Someone else has suggested this is not even possible).

I have been looking at this endpoint here which suggests it might be possible.
https://developers.shopware.com/developers-guide/rest-api/api-resource-orders/#post-(create)

I have been experimenting with this endpoint for a while. The challenge I am facing is, this endpoint needs a paymentId.

I then started looking at the endpoint REST API - Payment and payment instances

Maybe this endpoint can create provide me with a suitable paymentId?

I have more specific questions, but for now I would appreciate if someone can confirm I am on the right track.

Thanks.

https://developers.shopware.com/developers-guide/rest-api/api-resource-payment-methods/#search-results

This should be the right one to get the payment methods