how pass the value of a many2one field to a character field (Many2one--->Char), I don't know how to do (thank you in advance), Exemple :
Field Many2one and Char :
class ResCompany(models.Model):
    _inherit = 'res.company'
    manager_company = fields.Many2one('hr.employee')
class HrMission(models.Model):
    _name = 'hr.mission'
    manager_mission = fields.Char(string='manager', default=lambda self: self.default_manager())
    @api.model
    def default_manager(self):
       manager = self.env['res.company'].search([('manager_company','=', True).name
       return manager
 
    