Updating Field Mappings Parameter on table selection in Python Toolbox?

I am building a python toolbox with ArcPy and would like to associate an input feature class parameter with a field mapping, so that once user selects the input feature class the field map populates with the input fields.

I have tried;

• fieldMapParameter.addTable(feature_class_parameter.name) in the updateParameters method but throws error ParameterObject: Get attribute: addTable does not exist

• Setting fieldMapParameter.parameterDependencies = [param1.name] doesn’t seem to have an effect.

  def getParameterInfo(self):
      """Define parameter definitions"""
      feature_class_parameter = arcpy.Parameter(displayName="Input_Table", #0
                                      name="fc_settlements",
                                      datatype="DEFeatureClass",
                                      parameterType="Required",
                                      direction="Input")
  
      fieldMapParameter = arcpy.Parameter(displayName="Primary Settlement Fields", #1
                              name="primary_fieldmap",
                              datatype="GPFieldMapping",
                              parameterType="Optional",
                              enabled=True,
                              direction="Input" )
      fieldMapParameter.parameterDependencies = [feature_class_parameter.name] # Doesn't seem to work
      params = [feature_class_parameter,fieldMapParameter]
      return params
  
  def updateParameters(self, parameters):
      if parameters[0].altered:
         parameters[1].addTable(parameters[0].valueAsText) # Fails with method not found
      return
  

Full Toolbox

How do I associate these two parameters so they work like field mapping for the native tools such as Merge/Append etc ?