How to use the mixpanel-browser.alias function in mixpanel-browser

alias: (id: string) => {
    if (doTracking) { Mixpanel.alias(id); }
  },
  reset: () => {

alias: id => {
    if (envCheck) mixpanel.alias(id);
  },
  track: (name, props) => {

map(user => {
        if (!user.agreement) {
          this.authService.saveLoginRedirectPath(state.url);
          this.router.navigate(['/', 'agreement']);

          if (environment.analytics && environment.mixpanelKey) {
            const userHash = hashUserId(user.id);
            mixpanel.alias(userHash);
            mixpanel.identify(userHash);
          }
        } else {
          if (environment.analytics && environment.mixpanelKey) {
            const userHash = hashUserId(user.id);
            mixpanel.identify(userHash);
          }
        }

        return user.agreement;
      })
    );