Keep getting "MovieWriter ffmpeg unavailable; using Pillow instead." Error even though I have ffmpeg installed

Question

When trying to run the following code to output an .mp4 file of an animated bar graph, I keep getting "MovieWriter ffmpeg unavailable; using Pillow instead." Then at the bottom it states that I do not have ffmpeg installed. I've installed ffmpeg and added the path to my Environmental Variables. When I check for ffmpeg in my console, it does show my current version.

I also get an error that states that .mp4 is an unknown file extension.

That said, when I copy and paste my code into Google Colab, it saves the .mp4 file in the Files folder.

*import bar_chart_race as bcr
 import nflfastpy as nfl

 df = nfl.load_pbp_data(year=2021)
 df.head()
 ...
 df_weekly.index = 'Week ' + df_weekly.index.astype(str)

 bcr.bar_chart_race(df = df_weekly,
                   n_bars = 10,
                   sort='desc',
                   title='2021 Rushing Leaders by Week',
                   period_length=1000,
                   interpolate_period=False,
                   steps_per_period=10,
                   fixed_max=True,
                   filename = '2021_rushing_bar_chart.mp4')*