sAPT represents both your deposit and the rewards you earn on your APT each era (every 1 hour). There is no need to claim your rewards. Instead, sAPT acts as a share of the total pool of staked APT in Sokel. Since this pool accumulates staking rewards, your share (represented by your sAPT) enables you to withdraw more APT each era (~1 hour) at an APY of approximately 0.00%.