problem with cl_image_tag on Rails with Cloudinary-CodePudding

I've got a strange situation. Which is why I end up posting on Stackoverflow...

Basically, I've got a Ruby on Rails 6.1 app, running in production, on which I recently implemented Cloudinary (replacing Amazon S3). Cloudinary allows to get optimised pictures with custom sizes and format, so it's pretty amazing to use.

But I've got a problem with the cl_image_tag.

When running my code in local environment :

Putting this in development.rb :

  config.active_storage.service = :local

Causes this tag to fail to get the picture. Becauses it misses the main folder in which the image is stored (my_app/)

<%= cl_image_tag("homepage/banner.webp", quality: 'auto', width: 1932, height: 904) %>

So I have to write this instead if I want it to work :

<%= cl_image_tag("my_app/homepage/banner.webp", quality: 'auto', width: 1932, height: 904) %>

BUT if I do that, then my production environment will fail because it uses :

development.rb :

  config.active_storage.service = :cloudinary

index.html.erb :

<%= cl_image_tag("homepage/banner.webp", quality: 'auto', width: 1932, height: 904) %>

.env :

MEDIA_FOLDER_NAME_IN_CLOUDINARY=my_app

So I find myself stuck between one config working only in local, and one working only in production. What the heck ?! What am I missing ? I can't find anything on StackOverflow or Cloudinary's documentation.

Edit: My first guess is that the MEDIA_FOLDER_NAME_IN_CLOUDINARYenv variable is only loaded in the code if this line appears :

  config.active_storage.service = :cloudinary

But I can't use that in my local environment, so I have to find a workaround...

Thanks in advance for any help people