why file config/elasticquent not exists?

[netwons]

im used framework 5.7

[yinfuyuan]

You can find it in the documentation
https://github.com/elasticquent/Elasticquent#elasticsearch-configuration
After setup https://github.com/elasticquent/Elasticquent#elasticsearch-configuration
You have to execute
php artisan vendor:publish --provider="Elasticquent\ElasticquentServiceProvider"
add the elasticquent.php config file