Hey @webhk!
Thanks so much for confirming. That “SKU:” text is part of WooCommerce core if you’d like to take a look further.
We typically recommend using the free Say What plugin to adjust small amounts of text such as this.
If you opt to use that plugin, enter the following string as your “Original String” for your text adjustment:
SKU:
Then, you can use ‘woocommerce’ as your “Text Domain” and enter the text you would like to adjust it to as the ‘replacement string’, in this case, “Kod produktu”.
I hope that’s useful for you, could you let me know how you get on and if it does the job? ??
Cheers!