How to use the jsrsasign.hextob64u function in jsrsasign

// Copyright (c) Brock Allen & Dominick Baier. All rights reserved.
// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.

var jsrsasign = require('jsrsasign');
var rsaKey = jsrsasign.KEYUTIL.generateKeypair("RSA", 1024);
var e = jsrsasign.hextob64u(rsaKey.pubKeyObj.e.toString(16));
var n = jsrsasign.hextob64u(rsaKey.pubKeyObj.n.toString(16));

var path = '/oidc';
var metadataPath = path + '/.well-known/openid-configuration';
var signingKeysPath = path + '/.well-known/jwks';
var authorizationPath = path + '/connect/authorize';
var userInfoPath = path + '/connect/userinfo';
var endSessionPath = path + '/connect/endsession';

var metadata = {
    issuer: path,
    jwks_uri: signingKeysPath,
    authorization_endpoint: authorizationPath,
    userinfo_endpoint: userInfoPath,
    end_session_endpoint: endSessionPath,
};

// Copyright (c) Brock Allen & Dominick Baier. All rights reserved.
// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.

var jsrsasign = require('jsrsasign');
var rsaKey = jsrsasign.KEYUTIL.generateKeypair("RSA", 1024);
var e = jsrsasign.hextob64u(rsaKey.pubKeyObj.e.toString(16));
var n = jsrsasign.hextob64u(rsaKey.pubKeyObj.n.toString(16));

var path = '/oidc';
var metadataPath = path + '/.well-known/openid-configuration';
var signingKeysPath = path + '/.well-known/jwks';
var authorizationPath = path + '/connect/authorize';
var userInfoPath = path + '/connect/userinfo';
var endSessionPath = path + '/connect/endsession';

var metadata = {
    issuer: path,
    jwks_uri: signingKeysPath,
    authorization_endpoint: authorizationPath,
    userinfo_endpoint: userInfoPath,
    end_session_endpoint: endSessionPath,
};

function hashAccessToken(access_token) {
    var hash = jsrsasign.crypto.Util.hashString(access_token, "sha256")
    var left = hash.substr(0, hash.length / 2);
    var left_b64u = jsrsasign.hextob64u(left);
    return left_b64u;
}

generate_code_verifier(code_challenge: any): string {
        const hash = KJUR.crypto.Util.hashString(code_challenge, 'sha256');
        const testdata = hextob64u(hash);

        return testdata;
    }
}

private generate_at_hash(access_token: any): string {
        const hash = KJUR.crypto.Util.hashString(access_token, 'sha256');
        const first128bits = hash.substr(0, hash.length / 2);
        const testdata = hextob64u(first128bits);

        return testdata;
    }
}

private generate_at_hash(access_token: any): string {
        const hash = KJUR.crypto.Util.hashString(access_token, 'sha256');
        const first128bits = hash.substr(0, hash.length / 2);
        const testdata = hextob64u(first128bits);

        return testdata;
    }

OidcSecurityValidation.prototype.generate_at_hash = function (access_token) {
        var hash = KJUR.crypto.Util.hashString(access_token, 'sha256');
        var first128bits = hash.substr(0, hash.length / 2);
        var testdata = hextob64u(first128bits);
        return testdata;
    };
    OidcSecurityValidation.prototype.generate_code_verifier = function (code_challenge) {