Hi park jaehong,
Create an Export mapping, and use Message Definition to select your Attributes. In your Microflow, add export to the mapping Activity.
I suggest using Json to create your export mapping.
Export mapping : https://docs.mendix.com/refguide/export-mappings/
Any chat Documentation: https://docs.mendix.com/howto7/extensibility/charts-any-usage/
Cheat sheet for Any chart: https://docs.mendix.com/refguide/charts-any-cheat-sheet/
XPath constraints can be multiple lines. I advise you to follow some learning paths like this one: https://academy.mendix.com/link/modules/326/lectures/2500/8.1-Introduction