Facebook playable ad won't open scene, it stays on splash screen on fb preview

Hello! I’m struggling for a weak or so to find a way to make 3D playable ad. I tried with cocos creator because I’m familiar with it, but without the luck and now tried playcanvas and saw that similar problem is happening. Facebook preview app wont open the scene in both engines, it is accepted but stays on loading/splash screen so I can’t test does FbPlayableAd.onCTAClick() work and maybe see if it problem comes from a preview. Does anyone have idea how to resolve this?

I’m not such a good developer, so it is possible that I missed something simple or obvious.

Thank you!