How is Blockchain connected to GUI and other Output functions (SAP)


Hey, for my Job I am trying to get into Blockchain. Eventhough I just started by Boss already Comes up with complicated questions…

Maybe you guys can help me with one.
So if one implements a Blockchain to manage a Peer-2-Peer System like AirBnB, how do I manage to create an invoice? Most companies use SAP to create invoices that fit each specific Country law.
Can I feed SAP out of the Blockchain to create the invoices?

I thought that should be possible as it ist up to the programer to implement the specific API so in the end I could have the proper PDF Invoice, but I am far of certain about it.

Thanks in advance!