Do I need a second photo, a video or a prompt?
No. One photo is the only thing you upload. You do not film anything, you do not supply a reference video of someone else doing the trend, and you do not write a prompt: the pose, the timing and the closing hold are built into the generator.
You also do not need CapCut or any other app. The generator runs in the browser.
What to check in the finished clip
Video AI finds hands hard, and the bicep heart depends on a few fingers in the right place. Watch the clip from start to finish, not only the last frame, and look at four things: the heart gap is actually visible at phone size; the hand sits high on the upper arm, not down at the elbow; there are two arms, two hands and a plausible number of fingers; and your face, hair and outfit still look like the photo. Every clip uses the same simple indoor setting, so the background will not match your photo.
Also check that the same arm flexes the whole way through and that the hand does not melt into the muscle.
Why the heart does not close, and what helps
The most common misses are a heart that never closes, fingers that merge into the arm, a hand that lands too low, or an arm that is cropped by the frame. Most of them trace back to the photo: a hand that is out of frame, a sleeve covering the bicep, crossed arms, or a photo cut off at the shoulders.
A sharper waist-up photo with both hands visible and space above the head is the best fix. A new render is a new attempt, not a guaranteed correction, so fix the photo first. A render that fails outright returns its credits automatically.
The sound on your clip
By default Bicep Heart AI lays the original trend clip's sound back onto your video after rendering. Pick Silent before you render if you would rather choose a track inside TikTok or Instagram, where your account's music rules apply.
We do not license that audio for you. Brand and business accounts should use the platform's commercial music library or properly licensed music.