A lot more information please.
Are you trying to access from an internal LAN, or the Internet?
Is xyz.xyz.com.pl your domain?
What router and software version?
You will likely need to post your configuration
To export and paste your configuration (and I’m assuming you are using WebFig or Winbox), open a terminal window,
and type (without the quotes) “/export hide-sensitive file=any-filename-you-wish”. Then open the files section
and right click on the filename you created and select download in order to download the file to your computer.
It will be a text file with whatever name you saved to with an extension of .rsc. Open that file in your favorite
text editor and redact any sensitive information if desired / needed. Then in your message here, click the code
display icon in the toolbar above the text entry (the code display icon is the 7th one from the left and looks
like a square with a blob in the middle). Then paste the text from the file in between the two code words in brackets.
.
Search the forum for “hairpin NAT” because that is what you are looking for.
And post your config as requested below if you already attempted to configure hairpin