(SOLVED) Ramesete Trajectory planning build error

I’m following the WpiLib docs to implement path planning. As I’m creating my example trajectory, I get this build error saying “C:\Users\18082\Desktop\3721Command\3721Command\build\objs\frcUserProgram\release\frcUserProgramCpp\45vqxio4pi9nbs4dcvmcpqo1r\RobotContainer.o: in function RobotContainer::GetAutonomousCommand()': RobotContainer.cpp:(.text+0xd30): undefined reference to DriveConstants::KDriveKinematics’
collect2.exe: error: ld returned 1 exit status”

I see that my KDriveKinematics variable is located in my constants file under the DriveConstants namespace, but is there something I’m not seeing?

Robot Container File

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

#include "RobotContainer.h"
#include <utility>

#include <frc2/command/button/Trigger.h>
#include <frc/controller/PIDController.h>
#include <frc/controller/RamseteController.h>
#include <frc/shuffleboard/Shuffleboard.h>
#include <frc/trajectory/Trajectory.h>
#include <frc/trajectory/TrajectoryGenerator.h>
#include <frc/trajectory/constraint/DifferentialDriveVoltageConstraint.h>
#include <frc2/command/Commands.h>
#include <frc2/command/RamseteCommand.h>
#include <frc2/command/button/JoystickButton.h>
#include "commands/Autos.h"
//#include "commands/ExampleCommand.h"
#include "commands/Teleop.h"

RobotContainer::RobotContainer() {
  // Initialize all of your commands and subsystems here
  // Configure the button bindings

    &pchsDrive, [this] {return -m_driverController.GetLeftY();},
    [this] {return m_driverController.GetRightX();}));

void RobotContainer::ConfigureBindings() {

frc2::CommandPtr RobotContainer::GetAutonomousCommand() {
  // An example command will be run in autonomous
  frc::DifferentialDriveVoltageConstraint autoVoltageConstraint{
          DriveConstants::ks, DriveConstants::kv, DriveConstants::ka},
      DriveConstants::KDriveKinematics, 10_V};
  frc::TrajectoryConfig config{DriveConstants::kMaxSpeed,
  // Add kinematics 
  // Apply the voltage constraint

  // An example trajectory
  auto exampleTrajectory = frc::TrajectoryGenerator::GenerateTrajectory(
      // Start at the origin facing the +X direction
      frc::Pose2d{0_m, 0_m, 0_deg},
      // Pass through these two interior waypoints, making an 's' curve path
      {frc::Translation2d{1_m, 1_m}, frc::Translation2d{2_m, -1_m}},
      // End 3 meters straight ahead of where we started, facing forward
      frc::Pose2d{3_m, 0_m, 0_deg},
      // Pass the config
  frc2::CommandPtr ramseteCommand{frc2::RamseteCommand(
      exampleTrajectory, [this] { return pchsDrive.GetPose(); },
          DriveConstants::ks, DriveConstants::kv, DriveConstants::ka},
      [this] { return pchsDrive.GetWheelSpeeds(); },
      frc2::PIDController{DriveConstants::kPDriveVel, 0, 0},
      frc2::PIDController{DriveConstants::kPDriveVel, 0, 0},
      [this](auto left, auto right) { pchsDrive.TankDriveVolts(left, right); },

  // Reset odometry to the starting pose of the trajectory.

  return std::move(ramseteCommand)
          frc2::cmd::RunOnce([this] { pchsDrive.TankDriveVolts(0_V, 0_V); }, {}));

Constants File

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

#include <frc/kinematics/DifferentialDriveKinematics.h>
#include <frc/trajectory/constraint/DifferentialDriveKinematicsConstraint.h>
#include <units/acceleration.h>
#include <units/angle.h>
#include <units/length.h>
#include <units/time.h>
#include <units/velocity.h>
#include <units/voltage.h>
#include <numbers>

#pragma once
 * The Constants header provides a convenient place for teams to hold robot-wide
 * numerical or boolean constants.  This should not be used for any other
 * purpose.
 * It is generally a good idea to place constants into subsystem- or
 * command-specific namespaces within this header, which can then be used where
 * they are needed.

namespace DriveConstants{
    constexpr int RgtFPort = 6;
    constexpr int RgtBPort = 7;
    constexpr int LftFPort = 4;
    constexpr int LftBPort = 5;

    constexpr int kLeftMotor1Port = 0;
    constexpr int kLeftMotor2Port = 1;
    constexpr int kRightMotor1Port = 2;
    constexpr int kRightMotor2Port = 3;

    constexpr int kLeftEncoderPorts[]{0, 1};
    constexpr int kRightEncoderPorts[]{2, 3};
    constexpr bool kLeftEncoderReversed = false;
    constexpr bool kRightEncoderReversed = true;

    //Characterization Values (Change later)

    constexpr auto ks = 0.22_V;
    constexpr auto kv = 1.98 * 1_V * 1_s / 1_m;
    constexpr auto ka = 0.2 * 1_V * 1_s * 1_s / 1_m;

    constexpr double kPDriveVel = 8.5;

    //Drive Kinematics
    constexpr auto kTrackwidth = 0.69_m;
    extern const frc::DifferentialDriveKinematics KDriveKinematics;
    // Max Vel / Accl

    constexpr auto kMaxSpeed = 3_mps;
    constexpr auto kMaxAccl = 1_mps_sq;
    //Ramsete Param
    constexpr auto kRamseteB = 2.0 * 1_rad * 1_rad / (1_m * 1_m);
    constexpr auto kRamseteZeta = 0.7 / 1_rad;
    constexpr int kEncoderCPR = 1024;
    constexpr units::meter_t kWheelDiameter = 6_in; //Adjust later
    constexpr auto kEncoderDistancePerPulse =
        // Assumes the encoders are directly mounted on the wheel shafts
        (kWheelDiameter * std::numbers::pi) / static_cast<double>(kEncoderCPR);
namespace OperatorConstants {

constexpr int kDriverControllerPort = 0;

}  // namespace OperatorConstants

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