Did you update your spotify and clock apps? If you haven't, do that. Then open clock, go to alarm, hit the + symbol, tap alarm sound, and tap through to spotify and what playlist you want it to play.
I'm not on a zflip so I don't know if it's any different from my tablet in terms of steps.
Go to the "Clock" app on your phone then select "Alarm" on the bottom left corner of the phone if it isn't already selected, then tap on the + sign at the mid-right corner and set your alarm time and then click on "Alarm Sound" and select Spotify. Do make sure you sign in to your Spotify account.
