Message
Execution type must be filled in.
Cause
This error only appears when no ICP/ICV VAT codes are set in the administration settings.
Solution
In the integration, select the correct ICP VAT rate.
NOTE that this is a VAT rate with the code ICP in Twinfield.
If you still receive an error message that is identical to the image above, it means that the VAT settings are not properly configured in Twinfield. Go to Settings -> Administration settings in Twinfield. Check the following two settings:
Go to the VAT code settings and check which VAT group is set in this VAT rule;
Go to the settings of the selected VAT group and check if the box for ICP (Intracommunity performances) is checked.
Finally, the Abbreviated name in the VAT rate must be changed to ICP (case-sensitive).