All functions to create, reload and show rewarded video ads are included to RNAatkit module. So first you should import RNAatkit.
import {
RNAatkit,
} from '@addapptr/react-native-aatkit'
When AATKit is already initialized, you can create rewarded video placement. Just call createRewardedVideoPlacement function passing the placement name as parameter. Please note that the placement name has to be constant after once defined and cannot change with every app restart.
Then you can reload placement using reloadPlacement function. Also it's possible to let fullscreen ad to be auto-reloaded by calling startPlacementAutoReload.
RNAatkit provides more callbacks which might be useful, for example to get notified when rewarded video ad is loaded . To receive them, use NativeEventEmitter.