Requirement

DPL & ZPL Label printing from D365 Finance and operation browser using X++ Class.

Prerequisite

Install Document Routing Agent & at-least one active printer should be there in your D365 Finance and operation  environment.

https://docs.microsoft.com/en-us/dynamics365/fin-ops-core/dev-itpro/analytics/install-document-routing-agent

Sample Code

WhsDocumentRouting::printLabelToPrinter(“Your Active Printer Name”, ‘Your String or text’);

https://docs.microsoft.com/en-us/business-applications-release-notes/april19/dynamics365-finance-operations/advanced-wave-label-print