In Conversion Report, you can use Sub ID to track your orders.
Some offers don't have Sub IDs, in that case you can use Transaction ID from Conversion Report as your reference.
The transaction ID you see in the reports is the click ID generated upon each transaction. One click ID can generate multiple transactions which is why if you view the reports you will find multiple conversions coming from a common transaction ID.
Note: All offers do not allow to promote with Cashback Affiliate Sites, please refer to the offer general T&C before start promoting.