Except as provided in § 30-13-22 and § 30-13-68, a court-martial sentence, unless suspended, may be ordered executed by the convening authority when approved by him or her and his or her staff judge advocate or, in the absence of a staff judge advocate on the staff of the convening authority, by the staff judge advocate of the next highest command. The convening authority shall approve the sentence or such a part, amount, or commuted form of the sentence as the convening authority sees fit, and may suspend the execution of the sentence as approved by him or her.