Line 238 appears to be intended to be used as part of a shell script and is not a valid server.config line.
The fact it didn't complain about the lines before 238 seems to indicate you have a server.config that is an mix of confguration lines and shell script lines. You will have to carefully remove all shell script lines which have been accidently pasted into the server.config to proceed.
Also, please note, the guide you following is based around running OpenVPN Community Edition as packaged by Debian.
This is not the same thing as OpenVPN Access Server which can be found here:
https://openvpn.net/vpn-software-packages/
Unlike the community edition, with Access Server the configuration steps you are going through are done through a web portal.
If Access Server isn't the right solution for you, then you might want to consider using Debian's own documentation as a starting point as found here:
https://wiki.debian.org/OpenVPN