I’m unable to extract article text from that URL because it points to an MP3 audio file, not an HTML page containing written article content.
To give you what you asked for (pure markdown with the article title as H1 and the core article text), I would need access to a web page with textual content. An MP3 file does not contain embedded readable article text; it only stores audio data.
If you have a corresponding article page (for example, a news story or transcript linked on the Radio Pik site for that audio), please provide that HTML page URL, and I can then:
Czytaj cały artykuł u źródła — Polskie Radio PiK (Pomorza i Kujaw)