Add the RSS feed for the podcast into an RSS reeder and it should just be there? I tested with inoreader and the rss feed of Kvartal and it was attached.
I regularly transcribe podcasts and videos. I’ve found that the easiest way to do it is to paste the link into a service like TurboScribe rather than fussing with downloading mp3s. TurboScribe has a free tier, but if you have a lot of long files to transcribe, it’s worth subscribing to get them done quickly. I’ve found the quality of the transcriptions—which can include speaker identification—really good. (For English! I don’t know if the quality is a high in other languages.) You can play the track while you read the transcription right on the website and can download the transcription in a number of formats.
Just for fun I threw the episode’s link at TurboScribe’s free tier. You can check out the result here and see if it meets your standards.
Gemini (or at least the paid version) really is a good tool for audio transcription with speaker diarization. Turboscribe’s paid tier will transcribe long files, but I don’t think it will excise ads.