It works for me.

1. route/api.php
    Route::get('/user', [UserController::class, 'getusers'])->name('getusers;);

2. app\Http\Controllers\UserController.php

    public function getusers(Request $req) {
        $srcData = DB::table('user')->paginate($req->get('rows'));
        return json_encode($srcData);
    }

   note:  $req->get('rows')  is corespond for pageSize of datagrid

3. resources/view/user.blad.php

    <table id="dg2" class="easyui-datagrid"></table>

    <script>
    $(document).ready(function(){

        $('#dg2").datagrid({
            url: "{{route('getusers')}}",
            method: 'get',
            pagination: true,
            pagePosition: 'bottom',
            pageSize: 10,
            pageList: [10, 20, 50],
            loadFilter: function(data){
                return {"total": data.total, "rows": data.data}
            },
            ... other configurations ...
        });

    });
    </script>

    note:  loadFilter function is needed