can't use in laravel8

[Dark-flame-master1]

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

Problem 1
- naux/sendcloud[1.1, ..., 1.1.3] require illuminate/support ^5.1 -> found illuminate/support[v5.1.1, ..., 5.8.x-dev] but these were not loaded, likely because it conflicts with another require.
- naux/sendcloud[1.1.4, ..., 1.1.6] require illuminate/support ^5.5 -> found illuminate/support[v5.5.0, ..., 5.8.x-dev] but these were not loaded, likely because it conflicts with another require.
- Root composer.json requires naux/sendcloud ^1.1 -> satisfiable by naux/sendcloud[1.1, ..., 1.1.6].

Installation failed, reverting ./composer.json and ./composer.lock to their original content.