I get typeError when a try to print my costum report via wizard. below the code :

************In report python file**************

class ReportIncomeByDoctor(models.AbstractModel):

    _name = 'report.pragtech_dental_management.income_by_insurance'

    def get_income_insurance_company(self,start_date, end_date, insurance_company):
        invoice_obj = self.env['account.invoice']
        inv_dom = ([('date_invoice', '>=', start_date),
                ('date_invoice', '<=', end_date),('state','in',['open']), ('insurance_company','==',insurance_company)])
        tids = invoice_obj.search(inv_dom)        
        res = invoice_obj.browse(tids)
        return res
        
    @api.model
    def render_html(self, docids, data=None):
        self.model = self.env.context.get('active_model')
        act_ids = self.env.context.get('active_ids', [])
        docs = self.env[self.model].browse(act_ids)
        start_date = data.get('start_date', fields.Date.today())
        end_date = data['form'].get('end_date', str(datetime.now() +
                                    relativedelta(months=+1,
                                                  day=1, days=-1))[:10])
        insurance_company = data['form'].get('insurance_company')
        inv_act = self.with_context(data['form'].get('used_context', {}))        
        get_income_insurance_company = inv_act.get_income_insurance_company(start_date, end_date, insurance_company)
        docargs = {
            'doc_ids': docids,
            'doc_model': self.model,
            'data': data['form'],
            'docs': docs,
            'time': time,
            'get_income_insurance_company': get_income_insurance_company,
        }
        docargs['data'].update({'end_date':
                                parser.parse(docargs.get('data').
                                             get('end_date')).
                                strftime('%m/%d/%Y')})
        docargs['data'].update({'start_date':
                                parser.parse(docargs.get('data').
                                             get('start_date')).
                                strftime('%m/%d/%Y')})
        return self.env['report'].render('pragtech_dental_management.income_by_insurance', docargs)

class IncomeByInsuranceCompanyWizard(models.TransientModel):
    _name = 'income.by.insurance.company.wizard'

    _description ='Income By Procedure Wizard'
    date_start = fields.Date('From Date',required = True)
    date_end = fields.Date('To Date',required = True)
    insurance_company=fields.Many2one('res.partner', 'Insurance Company', required = True)
    
     
    @api.multi
    def print_report(self):
        data = {
            'ids': self.ids,
            'model': 'account.invoice',
            'form': self.read(['date_start', 'date_end', 'insurance_company'])[0]
        }
        
        value = self.env['report'].get_action(self, 'pragtech_dental_management.income_by_insurance', data)
        return value

Thanks for your help