Why aren't I getting my form data object with input values in this submit listener?

I have an HTML form, it's a pretty simple form, there's only 4 values that are required. It looks like this.

  

    

      Parameter
      
      
          Select a parameter
          Air humidity
          Air temperature
          Air pressure
        
    
    

        Unit
        
        

    
    

        Height
        
        
    
    

        Start time
        
        
    
    
  
  Show optional parameters
  

    

        End Time
        
    
    

        Max value
        
    
    

        Min value
        
    
    

        Number of frames
        
    
    

        Translation
        
    
    

        Power of linear interpolation
        
    
    

        list of omitted sensors
        
    
   
  
  

    Submit
  
 

And here is my JavaScript

$form.addEventListener('submit', (event) => {
  event.preventDefault()

  const formData = new FormData(event.target)
   // log our form object
  console.log(formData)  
  event.target.reset()
  })

In my console log, why aren't I getting my form data object with properties and values on it that are set to the name value of my inputs as keys and values of the inputs as values? Instead I'm just getting an empty form data object.