Good afternoon... In an integer type field I am trying to convert the number into letters in a qweb report, I have this: 

def _amount_response(self): 

      for rec in self: rec.amount_response = str(rec.currency_id.amount_to_text(rec.amount_total)) 

amount_response = fields.Integer(string="Amount") 

In the qweb I am commanding to call the field in this way: 

And currency_id I am sending it to call from the py in this way: 

currency_id = fields.Many2one('res.currency', 'Currency', default=lambda self: self.env.user.company_id.currency_id.id) 

The problem here is that when I try to print the report in the qweb it gives me an error precisely in the qweb

 ValueError: Expected singleton: res.currency()

 Any solution? Odoo 14 community, thanks