custom primary key for transaction

app/models/sale_audit.rb

@@ -1,6 +1,6 @@
 class SaleAudit < ApplicationRecord
-#primary key - need to be unique generated for multiple shops
-  
+  #primary key - need to be unique generated for multiple shops
+
   belongs_to :sale
 
   def record_audit_void(sale_id, void_by, approved_by, reason)
@@ -50,4 +50,9 @@ class SaleAudit < ApplicationRecord
     sale_audit.remark = remark
     sale_audit.save!
   end
+
+  private
+  def generate_custom_id
+    self.sale_audit_id = SeedGenerator.generate_id(self.class.name, "SAI")
+  end
 end