Hello Team,

Could anyone please help me to resolve the below issue :
We are planning to integrate Gupshup wtih Salesforce platform and trying to get access_token using the bellow code snippet.
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Code Snippet :
/** This is a sample code for your bot**/
function MessageHandler(context, event) {
    context.console.log("test")
    var grant_type;
    var client_id;
    var client_secret;
    var redirect_uri;
    var username;
    var password;
   
    if(event.message.toLowerCase() == "post") {
    var contextParam = {
        "grant_type":"password",
        "client_id":"3MVG9Y6d_Btp4xp5fHfBCvTWgHlfBKxrEf0lFIt9p71zfTmei0q9P8QxoaRowTIefchOoNdY8syyWOriUKYlV",
        "client_secret":"7975635620731036814",
        "redirect_uri":"https://localhost:8443/_callback",
        "username":"apex_integration@sfdc.com",
        "password":"Mardal786*k7Q58cu1ffXZEm0NOEgWi8vIv"
    };
    var url = "https://login.salesforce.com/services/oauth2/token";
    var param = JSON.stringify(contextParam);
    var header = {"Content-Type":"application/x-www-form-urlencoded"};
    context.console.log("contextparm")
    context.simplehttp.makePost(url,param,header);
    }
}
/** Functions declared below are required **/
function EventHandler(context, event) {
    if(! context.simpledb.botleveldata.numinstance)
        context.simpledb.botleveldata.numinstance = 0;
    numinstances = parseInt(context.simpledb.botleveldata.numinstance) + 1;
    context.simpledb.botleveldata.numinstance = numinstances;
    context.sendResponse("Thanks for adding me. You are:" + numinstances);
}
function HttpResponseHandler(context, event) {
    context.console.log(event.getresp)
    var result= JSON.parse(event.getresp);
    if(result=="success"){
        context.console.log("success")
       context.sendResponse("We have successfully stored your data");
       }
    context.sendResponse(event.getresp);
    context.console.log("final")
}
function DbGetHandler(context, event) {
    context.sendResponse("testdbput keyword was last get by:" + event.dbval);
}
 
function DbPutHandler(context, event) {
    context.sendResponse("testdbput keyword was last put by:" + event.dbval);
}

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Error Dexcription :

{"error":"unsupported_grant_type","error_description":"grant type not supported"}

Any help would be greatly appriciated.

Thanks,
Fazur