To satisfy the condition, you'll need to make a certain number of segments into helixes. If you hover the "Secondary Structure" condition in the condition area, you'll see that 15 residues (or segments) should be in helixes.
At the start, none of the segments of the puzzle are in a helix.
Use Structure Mode to create the necessary helixes. Structure mode can be selected via Modes -> Structure Mode or using the "2" keyboard shortcut.
In structure mode, hover over a segment, right click, and select "Assign Helix" from the wheel menu. After making one segment into helix, you can click on the segment and drag to "paint" adjacent segments as helix.
Although you could, don't simply make one large helix. Instead, make at least two helixes. Leave one, two, or three loop segments between your helixes.
After marking the helixes in structure mode, you still need to get them into shape. Go back to Pull Mode via Modes -> Pull mode or using the "1" keyboard shortcut. Then right-click on a segment of one helix and select "Ideal SS" from the wheel menu. Repeat this for the other helix(es).
In some cases, simply making the helixes may be enough to solve the puzzle. Even if this happens, you may want to try experimenting with Building Blocks to see their effect on the protein.
Assuming you made two helixes, locate a suitable building block and drag to the appropriate spot in the Blueprint window. An appropriate building block would be in the Helix-Helix section, and would have the same number of loop segments that you left between your helixes. If you left only one loop segment, there's only one suitable building block. If you left two or three loop segments, there are two building blocks for each.
In the Blueprint window, drop your selected template on the appropriate spot, lining up the helix and loop indicators.
After applying the building block, trying wiggle and shake. If the puzzle still needs work, try a different building block, or try dragging the building block off the template and wiggling and shaking again.
This is fairly easy puzzle, but if you're having difficulty, reset and try again.