Adding browser field and setting variable

Question

Good day, all!

I'm trying to create very simple addon that will makes my everyday life a bit more convenient. It applies all transformation of selected object, deleting all material slots and export two versions of selected object - triangulated and quad version.

Here's my code:

import bpy
import os

basedir = os.path.dirname(bpy.data.filepath)
selection = bpy.context.selected_objects

# if not basedir:
#    raise Exception("Blend file is not saved")

view_layer = bpy.context.view_layer

obj_active = view_layer.objects.active
selection = bpy.context.selected_objects

def main(context):

    for obj in selection:
    
        obj.data.materials.clear()
    
        bpy.ops.object.transform_apply(location=True, rotation=True, scale=True)
    
        bpy.ops.object.modifier_add(type='TRIANGULATE')
        bpy.context.object.modifiers["Triangulate"].keep_custom_normals = True

        obj.select_set(True)

         # some exporters only use the active object
        view_layer.objects.active = obj

        name = bpy.path.clean_name(obj.name)
        fn = os.path.join(basedir, name)
        path = "D:/SVN/Characters/Models/"

        bpy.ops.export_scene.fbx(filepath=path + name + ".fbx", use_selection=True)
    
        bpy.ops.object.modifier_remove(modifier="Triangulate")

        print("Triangulated mesh has been written:", fn)
    
        bpy.ops.export_scene.fbx(filepath=path + name + "_quad.fbx", use_selection=True)
    
        print("Quad mesh has been written:", fn)    

        obj.select_set(False)

        view_layer.objects.active = obj_active

for obj in selection:
    obj.select_set(True)
    
class SaveTrisAndQuad(bpy.types.Operator):
    """Export quad and triangulated meshes, apply transforms and delete materials"""
    bl_idname = "object.savetrisandquad"
    bl_label = "Save tiangulated and Quad mesh"
    
    def execute(self, context):
        main(context)
        return {'FINISHED'}
    
# Creating Panel ======================================

class RedNeckPanel(bpy.types.Panel):
    bl_label = "RedNeck Tools"
    bl_idname = "OBJECT_PT_redneck"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'
    bl_category = "RedNeck"

    def draw(self, context):
        layout = self.layout
        obj = context.object
        row = layout.row()
        row.operator(SaveTrisAndQuad.bl_idname, text="Export Mesh", icon='EXPORT')
        
        

# Creating Panel ======================================
    
from bpy.utils import register_class, unregister_class

_classes = [
    SaveTrisAndQuad,
    RedNeckPanel
]


def register():
#    bpy.utils.register_class(SaveTrisAndQuad)
    for cls in _classes:
        register_class(cls)
    
def unregister():
#    bpy.utils.unregister_class(SaveTrisAndQuad)
    for cls in _classes:
        unregister_class(cls)    
    
if __name__ == "__main__":
    register()

It works just fine, but the only problem is that "path" variable is hard coded. How can I add browse button to be able to choose a path to save file to and how can I set a "path" variable from this selection?

Can someone please point me in right direction. I've tried to google it, but can't really find what I need and blender API documentation is kinda confusing.

Thanks.