Is there a certain level ican our case the extended energy bar?

I thought that the Increased Capacity Bar is available from the start. Tap on the green "+" next to your energy bolts. The offer should be the 3rd on the list and costs 799 purple diamonds. If not, try switching tabs/stores at the bottom of that page. Offer is only available in the lightning bolt tab.

You'll get 3 bars full to start (450 energy). After that, the bar will automatically refill to 150 energy bolts in 5hr, instead of 110 in 3hr 20min. It will remain a permanent feature in your game. Plus, all album jigsaw puzzles you complete or star boosters you activate will give you a full bar of 150 energy bolts.

After you purchase the Increased Capacity Bar, the offer will be replaced by an offer for 3 bars of energy for 139 diamonds.