Installing sluggable for Laravel on OpenServer?

Question

open server

Can't install sluggable for Laravel
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - cviebrock/eloquent-sluggable[8.0.0, ..., 8.0.1] require illuminate/config ^8.0 -> found illuminate/config[v8.0.0, ..., 8.x-dev] but it conflicts with another require.
    - Root composer.json requires cviebrock/eloquent-sluggable ^8.0 -> satisfiable by cviebrock/eloquent-sluggable[8.0.0, 8.0.1].

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

Installation failed, reverting ./composer.json and ./composer.lock to their original content.
Tell me what I'm doing wrong, composer I updated.