Approvals: StorageDescriptor<
    [{ interior: XcmV3Junctions; parents: number }, SS58String, SS58String],
    { amount: bigint; deposit: bigint },
    true,
    never,
>

Approved balance transfers. First balance is the amount approved for transfer. Second is the amount of T::Currency reserved for storing this. First key is the asset ID, second key is the owner and third key is the delegate.