strtolower() expects parameter 1 to be string, object given.

[airliajsmith]

Not sure if this is a problem through Laravel-Excel or my lack of coding skills.

Here is the code that is giving me the error:
Controller
`
$lastPayPeriod = $this->punchService->getLastPayPeriod();
$startDate = $lastPayPeriod->start;
$endDate = $lastPayPeriod->end;

    return (new TimecardExport())->startDate($startDate)->endDate($endDate)->download('timecards.xlsx');

Export File:

public function startDate(string $startDate)
{
    $this->startDate = $startDate;

    return $this;
}

public function endDate(string $endDate)
{
    $this->endDate = $endDate;

    return $this;
}

public function view(): View
{
    return view('hr.punches.export.timecards', [
        'punches' => Employee::where('active', 1)
            ->where('salary', 0)
            ->with('punches', 'user')
            ->has('punches', function (\Illuminate\Database\Eloquent\Builder $query) {
                return $query->where('date', '>=', $this->startDate)
                    ->where('date', '<=', $this->endDate);
            })
            ->get()
    ]);
}

`
EDIT: Note than when I change (string $startDate) to (object $startDate), I get the opposite message:
strtolower() expects parameter 1 to be string, object given

[airliajsmith]

This was my fault. I had to change 'has' to 'whereHas'