Row Formatting Excel Export Array Dynamically

[balamurugan1991]

I want to Format Excel Some rows Need to make as Bold. I try Lots of ways But Noting Working.
I am beginner for Laravel Excel. Can anyone guide me how to Format Custom Rows Dynamically.

For Example : -

I want this Above Format. If age is Above 30 i want to Bold the Rows. If i try Export from View it will take too Much time. becoz 1M records exist in my db. I try excel export from array also this is multiple sheets Export. Can anyone guide me.

I try the Below code to Bold the Headers, using register events : -
`public function registerEvents(): array {

    return [
        AfterSheet::class => function(AfterSheet $event) 
        {
            /** @var Sheet $sheet */
            $sheet = $event->sheet;              
            
            $styleArray = [
                'alignment' => [
                    'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER,
                    'vertical' => \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER,
                ],
            ];
            
            $cellRange = 'A1:AC1'; // All headers
            $event->sheet->getDelegate()->getStyle($cellRange)->applyFromArray($styleArray);
            $event->sheet->getDelegate()->getStyle($cellRange)->getFont()->setBold(true);
        },
    ];
}   `

I dont know how to do dynamically.