我遇到PHPfatalerror:找不到类'sendwithus\sendwithus_php\lib\API'Composer.json:{"repositories":{"sendwithus_php":{"type":"package","package":{"name":"sendwithus/sendwithus_php","version":"1.0.3","source":{"url":"https://github.com/sendwithus/sendwithus_php","type":"git","reference":"0dfed56"}}}},"require