laravel7版本composer require laravel/ui:"^2.0" 报错

教程：L05 Laravel 教程 - 电商实战 ( Laravel 7.x)

执行composer require laravel/ui:”^2.0”

报错信息：您的需求无法解析为一组可安装的包。改了几次国内镜像都不可以，不知道什么原因

# composer require laravel/ui:"^2.0"
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Conclusion: remove laravel/framework v5.7.17
    - Conclusion: don't install laravel/framework v5.7.17
   .
   .
   .
       - Installation request for laravel/framework (locked at v5.7.17, required as 5.7.*) -> satisfiable by laravel/framework[v5.7.17].
    - Installation request for laravel/ui ^2.0 -> satisfiable by laravel/ui[2.x-dev, v2.0.0, v2.0.1, v2.0.2, v2.0.3, v2.1.0].


Installation failed, reverting ./composer.json to its original content.