Jasconian Isle [Mystery Booster Playtest Cards 2019]

(Jasconian Isle isn't a spell, it's affected by summoning sickness, it's blue, and it has ": Add .")
Jasconian Isle enters tapped.
Jasconian Isle doesn't untap during your untap step.
At the beginning of your upkeep, you may pay . If you do, untap Jasconian Isle.