dicussion about the citybook react-native template

hi i have recently buy city-book react-native app from cth-hemes.i am having isues on that and they are not reply and didnot provide support for that .
problems i ahve ben facing
1 i am unable to undrstand how to use the api they have provided
2.on there documentation page named install plugin they have posted the the picture to generate the key they have not mentioned from where to open that page/website if any one know/or have purchased plz tell me