There is no feature that support the SAD document using the simplified method under article 33 a of the VAT Act.
According to this article, taxpayers have the option to settle VAT of the import of goods without having to pay the tax in advance to the customs office.
In this case tax should be post to Sales tax payable and Sales tax receivable.
In Dynamics 365 we have only opportunity to post document SAD to Sales tax payable and Vendor balance.

https://www.lexlege.pl/ustawa-o-podatku-od-towarow-i-uslug/art-33a/

It would be good to add this to Dynamics 365 F&O