I don't quite get why this doesn't work

// Code modifications are CC0-1.0

//WorldWeapons.cxx
-   bz_ServerShotFiredEventData_V1 event;
+   bz_ServerShotFiredEventData_V2 event;
    event.guid = shotGUID;
    event.flagType = allowEvent.flagType;
    event.speed = shotSpeed;
+   event.shotID = firingInfo.shot.id;
    for (int i = 0; i < 3; i++)
    {
        event.pos[i] = origin[i];
        event.velocity[i] = firingInfo.shot.vel[i];
    }

// bzfsAPI.h
class BZF_API bz_ServerShotFiredEventData_V1 : public bz_EventData
{
public:
    bz_ServerShotFiredEventData_V1() : bz_EventData(bz_eServerShotFiredEvent)
        , guid(0)
        , speed(0)
        , team(eRogueTeam)
    {
        pos[0] = pos[1] = pos[2] = velocity[0] = velocity[1] = velocity[2] = 0.0f;
    }

    uint32_t guid;
    bz_ApiString flagType;
    float speed;
    float pos[3];
    float velocity[3];
    bz_eTeamType team;
};

// Below code added:
class BZF_API bz_ServerShotFiredEventData_V2 : public bz_ServerShotFiredEventData_V1
{
public:
    bz_ServerShotFiredEventData_V2() : bz_ServerShotFiredEventData_V1(), shotID(-1)
    {
    }

    int shotID;
};
// Above code added:


// Below is an error of trying to compile a plug-in:
/*
serverShotAPI.cpp: In member function ‘virtual void serverShotAPI::Event(bz_EventData*)’:
serverShotAPI.cpp:91:9: error: ‘bz_ServerShotFiredEventData_V2’ was not declared in this scope; did you mean ‘bz_ServerShotFiredEventData_V1’?
   91 |         bz_ServerShotFiredEventData_V2* shotData = (bz_ServerShotFiredEventData_V2*)eventData;
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |         bz_ServerShotFiredEventData_V1
serverShotAPI.cpp:91:41: error: ‘shotData’ was not declared in this scope
   91 |         bz_ServerShotFiredEventData_V2* shotData = (bz_ServerShotFiredEventData_V2*)eventData;
      |                                         ^~~~~~~~
serverShotAPI.cpp:91:84: error: expected primary-expression before ‘)’ token
   91 |         bz_ServerShotFiredEventData_V2* shotData = (bz_ServerShotFiredEventData_V2*)eventData;
*/

// The command used to compile it:
// g++ -I /home/path-to-bzflag-mod/bzflag-2.4.26-api-mod/include/ -shared -fPIC -o serverShotAPI.so serverShotAPI.cpp

// The plugin code itself:
// serverShotAPI.cpp
// License: CC0-1.0

#include "bzfsAPI.h"

class serverShotAPI : public bz_Plugin, bz_CustomSlashCommandHandler
{
public:
  const char* Name(){return "serverShotAPI";}
  void Init ( const char* commandLine );
  void Event(bz_EventData *eventData );
  void Cleanup ( void );
  bool SlashCommand ( int playerID, bz_ApiString command, bz_ApiString message, bz_APIStringList* params );

};

BZ_PLUGIN(serverShotAPI)

void serverShotAPI::Init (const char* commandLine) {
  bz_registerCustomSlashCommand ( "shot", this );
  Register(bz_ePlayerDieEvent);
  Register(bz_eServerShotFiredEvent);
}

void serverShotAPI::Cleanup (void) {
  bz_removeCustomSlashCommand ( "shot" );
  Flush();
}

bool serverShotAPI::SlashCommand ( int playerID, bz_ApiString command, bz_ApiString message, bz_APIStringList* params ) {
  if (command == "shot"){
    float vector[3]={0.0, 0.0, 0.0};
    float origin[3]={0.0, 0.0, 0.0};
    uint32_t shotGUID = bz_fireServerShot("LF", origin, vector, bz_getPlayerTeam(playerID));
    bz_sendTextMessagef(BZ_SERVER, BZ_ALLUSERS, "ShotOnDemand: ShotGUID is: %u", shotGUID);
    return true;
  }
  return false;
}

void serverShotAPI::Event(bz_EventData *eventData ){
  switch (eventData->eventType) {
      case bz_ePlayerDieEvent: {
      //int playerID=((bz_PlayerDieEventData_V2*)eventData)->playerID;
      bz_PlayerDieEventData_V2* deathData = (bz_PlayerDieEventData_V2*)eventData;
      bz_sendTextMessagef(BZ_SERVER, BZ_ALLUSERS, "DieEvent: ShotID is: %d", deathData->shotID);
    }break;

      case bz_eServerShotFiredEvent: {
        bz_ServerShotFiredEventData_V2* shotData = (bz_ServerShotFiredEventData_V2*)eventData;
        bz_sendTextMessagef(BZ_SERVER, BZ_ALLUSERS, "ShotEvent: ShotID is: %d, ShotGUID is: %u", shotData->shotID, shotData->guid);

// Data
// ---
// (uint32_t)     guid - The GUID of the shot that was fired
// (bz_ApiString) flagType - The flag abbreviation of the shot type that was fired
// (float)        speed - The speed of the shot fired
// (float[3])     pos - The position of where the shot was fired (x, y, z coordinates)
// (float[3])     velocity - The vector of the shot's direction multiplied by the shot's speed
// (bz_eTeamType) team - The team this shot belongs to
// (double)       eventTime - This value is the local server time of the event.

    }break;

    default:{
    }break;
  }
}