I found two solutions on the Internet (unable to solve it!):
Failed to solve the problem, please solve it...??
认证0级讲师
Add this to your composer.json file
"repositories": [ { "type": "composer", "url": "https://packagist.org" }, { "packagist": false } ]
Then:
composer clear-cache composer install
Add this to your composer.json file
Then: