If you only need to access one client with ICMP, then routes are not necessary. Make sure you specify the LAN host IP address in the destination address field of the firewall rule and try pining the RUT241 virtual IP address. The ICMP packets wilk get forwarded to the LAN client.
Please follow the guide on configuring OpenVPN with routes here: https://wiki.teltonika-networks.com/view/OpenVPN_configuration_examples_RUT_R_00.07
Alternatively, remove any created/modified firewall rules and setup Port forward from OpenVPN zone to LAN zone and destination host 192.168.1.147. Make sure to allow all protocols.
This way you will be able to reach the LAN device using the virtual IP 10.2.0.x.