OpenVPN Client - Set static IP in client config instead of DHCP

I need my OpenVPN clients to always have the same IP address when they connect to the VPN. Is it possible for me to set a static IP in the OpenVPN client config file instead of them using DHCP and getting whatever IP address the DHCP server on the Peplink gives them?

From what I’ve read it’s not possible to do this on the Peplink side because the Peplink can’t do DHCP reservation for OpenVPN clients. The only way is with a Radius server, which I can’t do.