In 6-quart Instant Pot™ insert, place water. Place rack in insert. Place squash on top of rack. Secure lid; set pressure valve to SEALING. Select MANUAL; cook on high pressure 16 minutes. Select CANCEL. Set pressure valve to VENTING to quick-release pressure. Place squash on cutting board. Remove rack, and drain off cooking liquid. When cool enough to handle, using spoon, scrape squash from peel. Set aside.