Update to drupal 9 with composer

Hello,

I'm trying to update a website in drupal 8 to drupal 9.
With the update status module, all is ok but when i try a composer up to last version of core 9 i have this error :

Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - drupal/ckeditor_widgets dev-1.x requires drupal/core ^8 -> found drupal/core[8.0.0-beta6, ..., 8.9.x-dev] but it conflicts with your root composer.json require (^9.1.13).
    - drupal/ckeditor_widgets 1.x-dev is an alias of drupal/ckeditor_widgets dev-1.x and thus requires it to be installed too.
    - Root composer.json requires drupal/ckeditor_widgets 1.x-dev -> satisfiable by drupal/ckeditor_widgets[1.x-dev (alias of dev-1.x)].

Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.

You have to know all my modules are up and it's ok on the last d8 core, it remains just the d9 core :)

Can you help me please ?