update : invoice entity

src/modules/invoices/entities/invoice.entity.ts

@@ -70,9 +70,9 @@ export class Invoice extends BaseEntity {
   @Column({
     type: 'enum',
     enum: InvoicePurpose,
-    nullable: false,
+    nullable: true,
   })
-  purpose: InvoicePurpose;
+  purpose?: InvoicePurpose;
 
   get isOverdue(): boolean {
     return this.status === InvoiceStatus.PENDING && new Date() > this.dueDate;