Smac Planner - Is it possible to make the robot Reverse (without changing heading)

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I have a Ackermann type robot (car) with turning radius 1. I was trying to tune smac planner (motion_model_for_search: "DUBIN") with RPP local planner. I am able to move the robot forward, but making it reverse isn't possible. Is it possible to make the robot move in reverse direction without changing its heading? If so can you please tell me which parameters allow me to do that.

I tried it with Redd_shepps too..

GridBased:
  plugin: "nav2_smac_planner/SmacPlanner"
  tolerance: 0.5 
  downsample_costmap: false    
  downsampling_factor: 1          
  allow_unknown: false     
  max_iterations: -1        
  max_on_approach_iterations: 1000 
  max_planning_time: 2.0        
  smooth_path: true   
  motion_model_for_search: "REEDS_SHEPP"
  angle_quantization_bins: 72    
  minimum_turning_radius: 1.5     
  reverse_penalty: 1.0  #For Reeds-Shepp model: penalty to apply if motion is reversing, must be => 1
  change_penalty: 0.20 #0.20       
  non_straight_penalty: 1.05        
  cost_penalty: 1.3           
  smoother:
    smoother:
      w_curve: 30.0 #1.0         
      w_dist: 0.0             
      w_smooth: 30000.0           
      w_cost: 1.0 #0.025           
      cost_scaling_factor: 10.0

However, when I created a new bt

    <root main_tree_to_execute="MainTree">
         <BehaviorTree ID="MainTree">
            <PipelineSequence name="NavigateWithReplanning">
               <DistanceController distance="1.0">
                      <ComputePathToPose goal="{goal}" path="{path}" planner_id="GridBased"/>
               </DistanceController>
               <FollowPath path="{path}"  controller_id="FollowPath"/>
                <Wait wait_duration="2"/>
                <BackUp backup_dist="2.0" backup_speed="1.0"/>
            </PipelineSequence>
         </BehaviorTree>
     </root>

And tried running the above config, because of backup recovery_server it starts to backup. Is backup plugin a must?