Amateur using MS Teams needs easy steps to transcribe an MP4 recording into editable text.

Hi;

I have tried multiple ways, which until recently wasn't necessary; I waited until the MS Teams recording was ready; then I downloaded (it automatically downloads into an MP4 format), then I saved it and opened it in MS Notepad, which opened in American English.  Now it opens in gibberish, and I can't use MS Word Transcribe because the recording is over 1 hour long.  How can I do this as an amateur user?  Thank you for your help; even AI isn't helping with this.