Firstly, install and configure SoftEther VPN Server and then follow the installation and setup steps:
Step 1: Download SoftEther VPN Server.
Step 2: Run the Installer and do initial Configuration.
Step 3: Forward ports on router and add firewall rule.
Step 4: Reserve IP address for the VPN Server machine and set up DHCP reservation on router.
Step 5: Assign static IP address to PC (Windows 10) and set up VPN connection on Client PC.