Hello,
I’m trying to synchronise the steps of a character in a video with the rhythm of a song. I know the bpm but you seemingly can’t set a custom sound for the rhythm track and choose from a limited choice.
Unfortunately, I’m currently unable to access Audacity to check its version, but I will do so ASAP.
Any help will be appreciated 
Try this old plug-in: Metronome looper
Works great, thanks! 
I’ve noticed that there’s a small bug in that plug-in. I don’t think it will affect your use case, but just so that you are aware of it:
The plug-in “should” just use the first 1 second of the selected audio as the “custom sound”, but if the pitch shift is set to zero (no pitch shift), then the entire selection is used even if it is longer than 1 second.
I’m guessing that your custom sound is less than 1 second, so the bug will not appear.
I’ll see about fixing the issue when I get time.