Hi irina-hameza-ewa,

That is correct, with the new GST Centre we can switch tax rate from Simple to Detailed GST but unfortunately the system does not provide the custom tax rate feature anymore. If interested in switching to Detailed GST to you can see more info by clicking here.

If you interested in switching to Detailed GST please click here to get in touch with our friendly team for support. 

Thanks, 

-Steven