bug using QRcode in laravel 5.5

[ylapin]

this is a general error and it's not important which number I put always the same error
also it's a problem because I wanted to encode a url, not a number but anyway it's not working

production.ERROR: imagecreate(): Invalid image dimensions {"exception":"[object] (ErrorException(code: 0): imagecreate(): Invalid image dimensions at /projects/vendor/milon/barcode/src/Milon/Barcode/DNS1D.php:171)
[stacktrace]
#0 [internal function]: Illuminate\Foundation\Bootstrap\HandleExceptions->handleError(2, 'imagecreate(): ...', '/projec...', 171, Array)
#1 /projects/vendor/milon/barcode/src/Milon/Barcode/DNS1D.php(171): imagecreate(0, 30)
#2 /projects/vendor/milon/barcode/src/Milon/Barcode/DNS1D.php(2456): Milon\Barcode\DNS1D->getBarcodePNG('438436', 'QRCODE')
#3 /projects/app/Library/functions.php(278): Milon\Barcode\DNS1D::__callStatic('getBarcodePNG', Array)