RAR command line - Exclude all directories

I have the following structure :

FOLDER :

• file1
• file2
• file3
• subfolder1
  • file1.1
  • file1.2
• subfolder2
  • file2.1
  • file2.2

I would like to create an archive with the files in the root only (excluding all subfolder nevermind their name)

I tried : rar a archive.rar FOLDER and rar a -r- archive.rar FOLDER

Both case, the archive is empty

By documentation it should be rar a -r archive.rar D:\path\to\FOLDER\*