Question UnityAds Sdk and Ad usage

Hello friends,

I want to ask you a few questions.
1-) I call the sdk.cs file in the intro scene of the game. The actor switches from there to a different scene. Do I need to call sdk.cs again in the newly passed scene?

2-) After showing the interstitial, I want it to show the interstitial again after a few scenes, but it doesn't. Do I need to call sdk.cs to show ads again after the first ad is shown? Or do I have to destroy the ad and call it again?

3-) Do I need to call the Load method again after the ad is shown?

Thank you in advance for your answers.