A Form BOC-3 designates an authorized person or an office to accept any legal papers on your behalf in any state you conduct business and/or traverse through, and then forward them to you.
https://www.aprocessagents.com/online-application/
All truckers for hire, brokers, or freight forwarders must file a BOC-3 (Process Agents) form with the Federal Motor Carrier Safety Administration (FMCSA) before their authority will be issued.
https://www.aprocessagents.com/