If you use UnityAds directly without mediation, please go to Monetization Dashboard > Monetization > Ad Units > ... (on the right) > Edit ad unit
If you use a mediation, please go to Monetization Dashboard > Monetization > Placements > ... (on the right) > ... (on the right) > Edit ad unit and placement
NOTE: Skipping is disabled by default for the rewardedVideo Placement.
For complete information on Ad Units, see our Ad Units documentation. We also recommend the Best practices guide for information on how to use Ad Units effectively.