Settlement of total income from the contract of mandate from Poland and the Netherlands?

[CarlosHunter]

Hello.
I am asking for help in settling the income obtained in Poland and the Netherlands.
I am trying to settle this income in the e-pity program, but there are some cosmic taxes to pay ...
Help!

The taxpayer received PIT-11, which includes the following amounts:
item
49 - PLN
119,859.75 item
50 - PLN
11,142.42 item 51 - PLN 108,717.33 item 52 - PLN 5,770 item 70 - PLN 9,152.73
item 72 - PLN 4,464.55

Additionally, a certificate was attached to PIT-11 with the following text:

"The amount of income shown in the PIT-11 information includes, among others, income earned in the Netherlands in the amount of: PLN 59,525.98.
Pursuant to the agreement on avoidance of double taxation concluded between Poland and the Netherlands, the method of proportional deduction is applied to the settlement of income earned in the territory of the Netherlands.
The Contractor is entitled to a deduction of the tax paid in the Netherlands, the value of which is PLN 1,979.03.
The Contractor, in certain circumstances, may take advantage of the abolition allowance pursuant to Article 27g of the PIT Act. "