Integrating system data into Power BI - which way?

Hi. Power Bi gets data from databases or web services (doors that some softwares will open to let users query specific data). If you are working with any software you can take a look at the list of connectors that Power Bi has. If you can't find your software there, it's because it's probably not very popular or they haven't build a web service to let you connect. The best idea is always to communicate with software support and request a way to access your data. Depending on the companies they should assist you explaning how you can connect to the data. It could be because you have a database when the software was installed, or they have a web service available for you to use.

Depending on the answer, the type of connector you would use. Power Bi has almost all database connectors, if it doesn't have it, you can ask if you can connect with ODBC (it's a standard connection). If it's a web service you could probably connect to an API or OData (just naming so you can ask  to support).

I hope that helps,