Is there any option to activate SNMP on the firmware?
Vector
There is no snmp support in the firmware, so nothing to activate.
You need custom firmware, and compiled binary to setup snmp. This is requiring good network and linux knowledge.
They are snmp package compiled that you can find on the forum. They seems to have buggy answers for bandwith object request. I've done a snmp build, but it's 20 Mb tarball, so I won't post it here. snmpd executable is big also, and I cannot poll it every second, it will only answer every 2 seconds.
Your best option is to learn about the firmware, how to compile and to make your own snmp package.