You need to choose your code based on what you are selling. You can look up your industry code on the Stats Can website: North American Industry Classification System (NAICS) Canada 2022 Version 1.0 Or you can use the search tools on the NAICS website: NAICS & SIC Identification Tools

Thanks for the reply. I’m selling t-shirts and mugs. NAICS code should be 453998 but turbotax is still giving error. 

@darko-gataric To check what industry code applies to you, please refer to this CRA guide: North American Industry Classification System (NAICS) Canada 2022 Version 1.0

Unfortunately, we cannot suggest which industry code to use. For further clarification, please contact CRA.