You need to put PulsarApi.proto to a separate path.
Open your Wireshark.
Go to Edit > Preferences > Protocols > ProtoBuf > Protobuf, and then search paths.
Add the path of PulsarApi.proto.
Open Wireshark.
Go to About Wireshark > Folders > Personal Lua Plugins > Plugin Path.
Add pulsar.lua to this path.
This plugin registers a Pulsar protocol automatically in 6650. You can use it to decode Pulsar messages now.