Man pages matching name tshttptxnserverpackettosset in section 3ts:

TSHttpTxnServerPacketTosSet.3ts.en	debian 10 / trafficserver-dev
TSHttpTxnServerPacketTosSet.3ts.en	debian 11 / trafficserver-dev
TSHttpTxnServerPacketTosSet.3ts.en	debian 12 / trafficserver-dev