public class DocuSign1 {
    public String sendEnvelope(String email, String name){
        String accountID = '2e415cc6-****-45c0-****-396d6b465b47';
        String userName = 'b43dbb12-****-****-****-a83b9b70087b';
        String passWord = '*********';
        String integratorKey = '78cbd017-****-4d3d-****-a12656f122bf';
        String templateID = '82dfbae3-****-4a6a-****-4c6145ca39d3';
    //This Endpoint supports creating an envelope with the templateId.
        String endPoint = 'https://demo.docusign.net/restapi/v2/accounts/'+accountID+'/envelopes';
        //Apex HTTP Method Initialization
        HttpRequest req = new HttpRequest();
        req.setEndpoint(endPoint);
        req.setMethod('POST');
        //req.setMethod('POST');
        //Authorization header generating using DocuSign credentials.
        String authorizationHeader = '<DocuSignCredentials><Username>'+userName+'</Username><Password>'+Password+'</Password><IntegratorKey>'+integratorKey+'</IntegratorKey></DocuSignCredentials>';
        req.setHeader('X-DocuSign-Authentication', authorizationHeader);
        req.setHeader('Accept','application/json');
        req.setHeader('Content-Length','162100');
        req.setHeader('Content-Type','application/json');
        req.setHeader('Content-Disposition','form-data');
        //JSON Request which contains template id and receivers email and name.
        String json='{'+
            ' '+
            ' "emailSubject": "Agreement",'+
            ' "emailBlurb": "I am sending you this request for your electronic signature and enter or update confidential payment information.nnPlease review and electronically sign by following the link below. ",'+
            ' "templateId": "'+templateID+'",'+
            ' "envelopeIdStamping": "false",'+
            ' "templateRoles": ['+
            '  {'+
            '    "roleName": "Signer 1",'+
            '    "name": "'+name+'",'+
            '    "email": "'+email+'",'+
            '    "recipientId": "1"'+
            '   }'+
            ' ],'+
            ' "status": "sent"'+
            '}';
        req.setBody(json);
        Http http = new Http();
        HTTPResponse res;
        try{
            //Docusign Request Callout.
            res = http.send(req);
            system.debug('DocuSign Response'+ res.getBody());
        }
        catch(Exception e){
            ApexPages.addMessage( new ApexPages.Message(ApexPages.Severity.FATAL, e.getMessage()));
        }
        return json;
    }
}

<aura:component controller="DocuSign1" implements="force:hasRecordId,force:lightningQuickAction,force:appHostable,flexipage:availableForAllPageTypes,flexipage:availableForRecordHome,forceCommunity:availableForAllPageTypes" access="global">
            <aura:attribute name="tokenvalue" type="string"/>
            <lightning:button variant="brand" label="SignHere" onclick="{!c.handleNext}"/>
            <iframe id="abc" src="{!v.tokenvalue}" />
</aura:component>

({
    handleNext : function(component, event, helper) {
        console.log(component.get("v.recordId"));

        var action2 = component.get("c.sendEnvelope");
        action2.setParams({ "recordId" : component.get("v.recordId") });
        action2.setCallback(this, function(response1) {
            var state1 = response1.getState();
            alert(state1);
            if(state1 === "SUCCESS") {
                component.set("v.tokenvalue",response1.getReturnValue());
                //alert(response1.getReturnValue());
                //window.open(response1.getReturnValue());
            }
        });
        $A.enqueueAction(action2);
    }
})