How to add a save and load button in a Python-addin ArcGIS?

I would like to generate a tool in Python-Addin ArcGIS as the image attached. I also like to generate the save and load button in the tool. My purpose is that when the user chooses the range parameters and then clicks the save button, those parameters can be saved and next time if the user would like to reuse the parameter, they can load it. This is my python script but I do not know which types of python-addin should be put in my script

    import arcpy, arcgisscripting,math
    import pythonaddins
    import  pandas as pd
    import os, glob

    from arcpy import env
    arcpy.env.overwriteOutput = True
    arcpy.CheckOutExtension("Spatial")
    from arcpy.sa import *

    input=arcpy.GetParameterAsText(0)
    range_1=arcpy.GetParameterAsText(1)
    range_2=arcpy.GetParameterAsText(2)
    output=arcpy.GetParameterAsText(3)

    if (range_2==''):
       outFocalStat = FocalStatistics(input, NbrAnnulus(range_1, range_1, "CELL"),
                           "MINORITY", "NODATA")
    else:
       outFocalStat= FocalStatistics(input, NbrAnnulus(range_2, range_2, "CELL"),
                           "MINORITY", "NODATA")

    outFocalSat.save(output)