There are not many ways to convert an audio file to text without paying a lot of money.
Microsoft 365 provides this service:
Open a new document, then click on the transcribe icon in the top right corner 
Transcripts can be downloaded from YouTube, using DVDVideoSoft. They provide a Free YouTube to MP3 Converter, which downloads the audio files from single videos, playlists, or entire channels.
“All shall be well, and all shall be well and all manner of thing shall be well.” – Julian of Norwich