You have to head over to the main page to download the update: https://lockheart-novels.itch.io/a-moment-of-bliss
If that doesn't work, you'll need to head over to your purchases. Click on the down arrow in the top right hand corner of the screen, go down to 'My Library', on the left there will be a tab that says 'My Purchases'. A Moment of Bliss should be in there.