How do i create a Non taxable code?

Thanks for reaching out to the Community forum, @fshunnarah.

If you're using the old Sales Tax Center, you can edit the customer record by going to the Tax info tab and making sure that there is no checkmark for This customer is taxable.

However, if you're using the Automated Sales Tax, you can exempt your customer from sales taxes. Go to the Customer information window, then Tax info tab. Mark the This customer is tax exempt box and enter  Reason for exemption and the Exemption details.

If you have any other question about this process, let me know by commenting below. I'll be more than happy to offer additional assistance. Take care.