requires explicit declaration; provide the name of the package dependency with

[Acel-L]

there is an error when i build project
'webTestProj' /Users/ylbl/Desktop/webTestProj: error: dependency 'PerfectHTTPServer' in target 'webTestProj' requires explicit declaration; provide the name of the package dependency with '.package(name: "PerfectHTTPServer", url: "https://github.com/PerfectlySoft/Perfect-HTTPServer.git", from: "3.0.0")'
can someone help me, tell me how to do