added generateSignatureMode method

lib/av_client.ts

@@ -8,6 +8,7 @@ import { KeyPair, Affidavit, VerifierItem, CommitmentOpening, SpoilRequestItem,
 import { randomKeyPair } from './av_client/generate_key_pair';
 import { generateReceipt } from './av_client/generate_receipt';
 import { Buffer } from 'buffer'
+import * as Crypto from "../lib/av_client/aion_crypto.js"
 import jwtDecode, { JwtPayload } from "jwt-decode";
 
 import {
@@ -607,6 +608,10 @@ export class AVClient implements IAVClient {
     return this.keyPair.privateKey
   }
 
+  public generateSignature(payload: string): string {
+    return Crypto.generateSchnorrSignature(payload, this.proofOfElectionCodes.mainKeyPair.privateKey)
+  }
+
   /**
    * Registers a voter by proof of identity
    * Used when the authorization mode of the Voter Authorizer is 'proof-of-identity'