openvpn – VPN server behind router

I’m about to set up a Ubuntu server at home for hosting sftp and web. Currently I have installed OpenVPN Access Server in the server machine but it’s still not accessible externally as it’s behind my home router. As I know so far, there seems no alternatives to initiate the VPN connection from the client app on external devices, except using port forwarding to parse external requests from router to the server port that runs OpenVPN AS. Is this approach secured enough given I use a strong VPN password? Or otherwise, will there be any safer approaches to make the home server accessible from outside?