According to the sources, the recommended level for Kubfu to enter the tower is 70. However, it is possible to enter the tower with a lower level Kubfu. To level up Kubfu quickly, players can use Exp. Candies obtained from Max Raids or grind with Chansey in the grassy plains of the Isle of Armor. Additionally, players can raise Kubfus friendship level by traveling around the Isle of Armor and visiting specific locations marked on the map.