Seems like this question comes up about once a month. The documentation should explain this (haven’t I said this before?).
Besides the VPN connection, you have to open the firewall to permit access from the remote LAN. You have a connection, but you haven’t told the firewall its ok to let traffic in from the remote LAN.
Lets say the remote LAN is 192.168.100.0/24, you would create an inbound firewall rule:
You can tailor the source description to whatever devices on the remote that you want to allow access. For example maybe you only want one or two devices on the remote to be able to use the VPN, or maybe you want to allow every device.
Don’t forget you have to create the same rule at the remote destination, but substitute the LAN address for the opposite location.