This issue is occurring for Stick-IT-New USA Customer.
Error code:
Cannot import the order into the accounting system.
[{"ErrorCode":404,"Exception":"Active taxation rule with name Tax Exempt was not found in Taxation Rules reference book."}]
**The Retailer Tax code box nor Tax Code Type fields aren’t listed in advanced settings for retailer PGA Superstore**
PGA Superstore Test file: 4502608123TEST
For StickIT the retailer Dick's Sporting Goods is showing the Retailer Tax Code and the Tax Code type field. 
I asked Sam (USA) about this and Sam said: 


Please have the customer create the tax code "Tax Exempt" in Cin7/Core. 

The copy retailer settings workaround no longer works as it's been fully migrated to onlineservices and the retailer setting you're trying to copy does not exist in onlineservices for any retailer.


If there's a retailer setting you absolutely need, open a t2 ticket and we can manually add it to the sql db. make sure you include an example of a retailer that does have the setting. 


I submitted a Level 2 Helpdesk ticket and asked Level 2 to add these fields via SQL for PGA Superstore retailer so I can continue testing.