In order for the posting process to initiate the eInvoice Poland process, manual configuration needs to be done in the BTEs (Business Transaction Events) configuration transaction.
Transaction FIBF
It involves adding two entries associated with standard SAP events 1030 and 1050.
For each entry, the function module released by the product (/EINVO/PL_FC_FI_BTE_00001030 and /EINVO/PL_FC_FI_BTE_00001050 respectively) will be added.
There is the option to add a filter by country to activate it only based on the country of the company. To do this, the country would need to be added in the 'Ps' field.
Here is an example without a country filter:
