Updating Database phpmyadmin with codeigniter4

Im sorry im new in CI4,

I want to update my database with a form. But it can not update where i want to, even i put code where in it, if i delete the where code, they will update all of my record in my database, please ive been reading the documentation of CI4 and i still cant understand why my code can not detect the where code.

here's my code to update it

//update data name / bio
            $name = $this->input->post('name');
            $email = $this->input->post('email');
            $bio = $this->input->post('bio');
            $data = [
                'name' => $name,
                'bio'    => $bio
            ];
            $this->db->set($data);
            $this->db->where('email', $email);
            $this->db->update('user');