How to use laravel-er-diagram-generator with laravel 5.1

i am having problem to use laravel-er-diagram-generator package,with my laravel package, i have followed all the steps given in the doc.but when i run commad to generate erd i am facing following error

graphvis is installed correctly,when i check composer.json its also show entry from the package,i am using laravel 5.1 with php 7.2.27,can any one help me to point out whats going wrong? thanks

via Chebli Mohamed