Contract reference text format inside exported excel

app/Exports/SegmentContractsExport.php

@@ -11,11 +11,14 @@
 use Maatwebsite\Excel\Concerns\WithHeadings;
 use Maatwebsite\Excel\Concerns\WithMapping;
 use PhpOffice\PhpSpreadsheet\Shared\Date as ExcelDate;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 
 class SegmentContractsExport implements FromQuery, ShouldAutoSize, WithColumnFormatting, WithHeadings, WithMapping
 {
     public const DATE_EXCEL_FORMAT = 'dd"."mm"."yyyy';
 
+    public const TEXT_EXCEL_FORMAT = NumberFormat::FORMAT_TEXT;
+
     /**
      * @var array<string, array{label: string}>
      */
@@ -76,8 +79,16 @@ public function columnFormats(): array
         $formats = [];
 
         foreach ($this->columns as $index => $column) {
+            $letter = $this->columnLetter($index);
+
+            if ($column === 'reference') {
+                $formats[$letter] = self::TEXT_EXCEL_FORMAT;
+
+                continue;
+            }
+
             if (in_array($column, ['start_date', 'end_date'], true)) {
-                $formats[$this->columnLetter($index)] = self::DATE_EXCEL_FORMAT;
+                $formats[$letter] = self::DATE_EXCEL_FORMAT;
             }
         }