HELP I have 2 WD My Cloud EX2 I need them to sync

Hello Please help
I have one WD My Cloud EX2 in Apartment in the City and another WD My Cloud EX2 In Summer House.
Client wants those 2 Units to sync
If he adds a file to either one or deletes from either one He wants those units to be identical.
Is it possible if now what do I buy to make it possible?
Thank you
Really $20 for to anyone who will solve the problem for me,
Also He is asking if it will work with 3 Units ?


Please refer to the following KBA article:

Das mit dem Geld bieten für eine hilfreiche Antwort ist zwar “armselig”, aber wohl die einzige Möglichkeit in diesem Forum eine Antwort zu kriegen :stuck_out_tongue_winking_eye: