Change file permissions on VMOS for zANTI’s IP forwarding

I am using zANTI on VMOS (rooted, 32-bit). When I start MITM, it gives an error setting up IP forwarding

sh: <stdin>(2): can't create /proc/sys/net/ipv4/ip_forward: Permission Denied

So, I tried changing the file permission to execute with many different file explorers, but they just show success and don’t work.

Any solutions?