This article shares a possible use case your implementation could support, as well as a sample flow. You're not limited to this use case, but it can be a helpful jumping off point for your planning.
You can update the MX and TXT records for a domain purchased through Wix, and connect it to an external (non-Wix) site.
To update the DNS records for a domain:
You could help Wix site owners connect an external domain by nameservers to their site. Note that you can't use Update DNS Zone for external domains that are connected by pointing.
To connect an external domain by nameservers to a Wix site:
{"connectionType": "NAMESERVERS"}
.connectedDomainSetupInfo.pointingRecords.aRecord.values
and connectedDomainSetupInfo.pointingRecords.cnameRecord.value
.dnsPropagationStatus
and confirm that it
changes to "COMPLETED"
.