How to solved this ?

[sapitidur]

Non-static method Barryvdh\DomPDF\PDF::loadView() should not be called statically, assuming $this from incompatible context

$pdf=PDF::loadView('adm-sales.pdf',array('send'=>$sendpdf))->setPaper('A4');
return $pdf->download('send order.pdf');

[bebnev]

This happens because you are namespacing the wrong PDF class.
You are namespacing Barryvdh\DomPDF\PDF and try to use this class as "Facade" which is wrong.
So there are two posiible ways to solve your problem:

1. Setting namespace to the facade:

use Barryvdh\DomPDF\Facade as PDF;

2. Using alias (only if you add PDF alias to the app.php in the alias section):

use PDF;

[barryvdh]

Indeed, use the Facade.

[sagar720]

Non-static method Barryvdh\DomPDF\PDF::loadView() should not be called statically?..Help me out