Hi Milan!
You can retrieve your data while using a microflow in the same way that a database retrieve works.
In the XML you set the following:
property key="resources" type="datasource" isList="true" required="true">
<caption>Resource source</caption>
<description/>
In the widget settings in Studio Pro, you can choose multiple options for data retrieval. Be aware that it has to return a list, even if it is just one object.
This will be the pop-up to select the microflow:
Hope this helps!
Best regards, Stefan.