In this post I am asking about taxation of my income in Poland, this is why its in Polish.
**Edited for Community Guidelines**
Please take a look at this help article about reporting your income from Upwork which explains how to access the information about your earnings on Upwork. With regard to what documents you will need to supply in Poland when filing taxes, please seek the advice of a tax specialist for advice specific to your country, as we won't be able to advise on that.
I've edited your posts because as per our Community Guidelines, we ask that all users post in English, as it is the most common worldwide business language and we want to encourage other users to be able to understand and contribute. Thank you for your cooperation in this regard.