How to use the samlp.logout function in samlp

const parseLogoutRequest = function(req, res, next) {
    if (!req.idp.options.sloUrl) {
      return res.render('error', {
        message: 'SAML Single Logout Service URL not defined for Service Provider'
      });
    };

    console.log('Processing SAML SLO request for participant => \n', req.participant);

    return samlp.logout({
      issuer:                 req.idp.options.issuer,
      cert:                   req.idp.options.cert,
      key:                    req.idp.options.key,
      digestAlgorithm:        req.idp.options.digestAlgorithm,
      signatureAlgorithm:     req.idp.options.signatureAlgorithm,
      sessionParticipants:    new SessionParticipants(
      [
        req.participant
      ]),
      clearIdPSession: function(callback) {
        console.log('Destroying session ' + req.session.id + ' for participant', req.participant);
        req.session.destroy();
        callback();
      }
    })(req, res, next);
  }

app.post('/logout', (req: any, res: any, next: any): void => {

            samlp.logout({
                issuer: Config.saml_issuer,
                protocolBinding: 'urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST',
                cert: cert,
                key: key
            })(req, res, next);

        });