Why is there no access to samba through vpn?

Question

VPN

Good afternoon!
I have a tp-link Archer C6U router, I set up a VPN server on it and connected it to a USB HDD.
Set up DDNS via noip service. I hack from the phone via VPN PPTP, go to the file manager, get easy access to the HDD.
For some reason, when I create the same connection on windows, nothing works. What could be the reason?
Thank you very much in advance!