How to subscribe an OU to a tax regime in another country

We have a case where we are setting up an OU with country of United States. The US entity has a Tax Registration in Poland. We would therefore like to subscribe the US entity to an existing Polish Tax Regime. However, when entering Orders or Sales Transactions for this US entity, that are being shipped from an intercompany in Poland to a customer in Poland, no tax is being calculated.

We would expect the standard rate of Polish Tax to be applied.

Can someone help with a guide for what setups are needed?

We have Subscribed the US OU and Legal Entity to the Polish Tax Regime and created a Tax Registration for the same.