Yes, of course! When you have created your test and it’s ready to be published, you can choose who will take the test by selecting the ‘Share the test link with your own panel’ option. Remember that if your testers don’t have a UserQ account, you won’t be able to access demographic data.
Even if you do use a panel from UserQ, once your test is live, you’ll still be able access and distribute a link to your test to your own pool of testers too.