How to add SMS dialog in a custom app doctype

Hi I am trying to add Send SMS in my custom app. I have been able to add it in the menu but dont know how to pop up the dialog to send sms.
In erpnext 7 it was done by SMS manager but seems like it doesnt apply in erpnext 12. Kindly help.

I also want to send auto sms on submission of my document. E.g

on_submit: function(frm) {
Send sms function


@Mohammad_Ahmad_Zulfi Check this for your reference:

Thank you for your prompt reply. I will go through it and update.