PsychoPy cannot find the audio files

I am trying to add audio files to a trial but whenever I try to run the experiment it quits before the audio starts. According to the error message PsychoPy can’t find the audio files.
I’ve checked that I’m adding the right excel file and the correct path but it’s not working. I also checked I have the permission to use the files so that cannot be the issue either.
I used this tutorial: (I know it’s a bit old but I adjusted it to the PsychoPy version that I use).
I don’t know what I’m doing wrong, but I’d really appreciate some help.

Is this online or local? I use ogg locally and MP3 online. Wav works for both but MP3 doesn’t work locally.

OK, I think that explains the problem. I want to run it online but I wanted to test it locally first. Thanks for your answer. Now I just need to figure out why it’s not working online. It starts initialising but it never moves from there. I’m using Safari. Can it be the problem?

Update: I was trying to run it online but I kept getting various error messages (404, 403) I tested the solutions for these but they did not work. I just kept getting either one or the other error message, so I decided to convert my files to wav (as it was recommended in some other chats) and I tried to run it locally but it seems like it still cannot find the $audio. I’ve checked the path several times so I really don’t know what I’m doing wrong. Any suggestions?