Unable to open/submit the interactive dailog form using mmpy_bot plugin

Hello,
Hope you are doing good. We are looking to develop a interactive dialog which would provide the user the dropdown options to select from, as per the Mattermost documentation we are trying to open dialog using the json from plugin(mmpy_bot), but nothing seems to be happening. Basically trying to understand how can we get the trigger id and url as mentioned below. is URL is call back url of web hook id we create for the channel.? Could you please help understand the complete steps to open and submit the user dialog? Do we need to write server side integration , if so what are the steps to create a Mattermost development server instance for this to work… As I said we just started using mmpy_bot python libraries present in the Mattermost site to develop the BOT ,so any help would greatly help us?

{
“trigger_id”:“nbt1dxzqwpn6by14sfs66ganhc”,
“url”:“http://localhost:5000/dialog_submit”,
“dialog”:{
“callback_id”:“somecallbackid”,
“title”:“Test Title”,
“icon_url”:“Mattermost | Secure Collaboration for Technical Teams,
“elements”:[
{
“display_name”:“Display Name”,
“name”:“realname”,
“type”:“text”,
“subtype”:“”,
“default”:“default text”,
“placeholder”:“placeholder”,
“help_text”:“This a regng up the server instanc ular input in an interactive dialog triggered by a test integration.”,
“optional”:false,
“min_length”:0,
“max_length”:0,
“data_source”:“”,
“options”:null
},

Can someone please help here?