I'm testing NBDesigner before purchasing. It works great. I only need to figure out how to activate Pixabay and Unspash options in Photos Tab. None of them activates with default provided API keys, neither with my own. Facebook App ID works fine, but it's not the case regarding Pixabay and Unsplash. User manual indicates nothing else but typing APY Keys in backend Settings, but it doesn't work for me. 

¿Is it available only on Pro version?

¿Any suggestions?