How to share folders between 3 computer on different LANs

Hi everyone, i need to share a folder between 3 different PCs, on two different lan.
Until now I have successfully used HAMACHI from LogMeIn, but yesterday the logmein free trial expired and now to use HAMACHI I am required to use a LogmeinPro subscription at a price of 280 euros per year.

From what I understand Hamachi creates a VPN that simulates the connection between two computers on the same network; is there a way or similar software that allows me to share a folder between computers without having to use services like OneDrive?