Export to Excel 3.1, apply style and a report title

Someone knows some more complete documentation of Export Excel 3.1 I want to join cells for the name of my report and give them a style until now I just manage to put the header.

  public function headings(): array
     {
        return [
           'Indicador',
            'Nombre del Paciente',
            'Sexo',
            'No. seguro Social',
            'No. de Nomina'
        ];
     }
       public function map($row): array
       {
          return [
          $row->id_paciente,
          $row->nombre_pac,
          $row->sexo_pac,
          $row->nss_pac,
          $row->num_nomina_pac,

         ];
       }

I want to put on top of my header information like Title of the report uniting the corresponding cells date of accomplishment of reports etc., besides giving them a color style font type.

someone knows the functions that I should use ....