(1) A party or child support services agency seeking to modify, or to modify and enforce, a foreign child support order not under the convention may register that order in this state under Sections 81-8-601 through 81-8-608 if the order has not been registered.
(2) A petition for modification may be filed at the same time as a request for registration, or at another time.
(3) The petition shall specify the grounds for modification.