Você deve alterar o uso em seu aplicativo laravel via shell com o comando mysql
ALTER USER 'user'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'your password';
ALTER USER 'user'@'%' IDENTIFIED WITH caching_sha2_password BY 'your password';
ALTER USER 'user'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'your password';
ALTER USER 'user'@'%' IDENTIFIED WITH caching_sha2_password BY 'your password';