Hi @Colin Léger ,
Sincerest apologies with regards to the delayed response. If you created your WordPress site using the following marketplace template, then your folder content /wp-content/uploads/sites/16/2021/02/reynolds.jpg
will be a relative path under your wwwroot. I also confirmed that this folder is included inside an App Service backup.
If you used a different method in creating your WordPress site, please comment down below the steps you took. With regards to your plugin issue, can you further elaborate down below?