问在laravel 5.7中安装灯塔

EN

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

  Problem 1
    - Conclusion: don't install nuwave/lighthouse v2.6.4
    - Conclusion: don't install nuwave/lighthouse v2.6.3
    - Conclusion: don't install nuwave/lighthouse v2.6.2
    - Conclusion: don't install nuwave/lighthouse v2.6.1
    - Conclusion: don't install nuwave/lighthouse v2.6.0
    - Conclusion: remove webonyx/graphql-php v0.13.1
    - Installation request for nuwave/lighthouse ^2.6 
      -> satisfiable by nuwave/lighthouse[2.x-dev, v2.6.0, v2.6.1, v2.6.2, v2.6.3, v2.6.4].
    - Conclusion: don't install webonyx/graphql-php v0.13.1
    - nuwave/lighthouse 2.x-dev requires webonyx/graphql-php ^0.12 
      -> satisfiable by webonyx/graphql-php[0.12.x-dev, v0.12.0, v0.12.1, v0.12.2, v0.12.3, v0.12.4, v0.12.5, v0.12.6].
    - Can only install one of: webonyx/graphql-php[0.12.x-dev, v0.13.1].
    - Can only install one of: webonyx/graphql-php[v0.12.0, v0.13.1].
    - Can only install one of: webonyx/graphql-php[v0.12.1, v0.13.1].
    - Can only install one of: webonyx/graphql-php[v0.12.2, v0.13.1].
    - Can only install one of: webonyx/graphql-php[v0.12.3, v0.13.1].
    - Can only install one of: webonyx/graphql-php[v0.12.4, v0.13.1].
    - Can only install one of: webonyx/graphql-php[v0.12.5, v0.13.1].
    - Can only install one of: webonyx/graphql-php[v0.12.6, v0.13.1].
    - Installation request for webonyx/graphql-php (locked at v0.13.1) 
      -> satisfiable by webonyx/graphql-php[v0.13.1].