How can i transfer fund to a specific user by getting his/her userID? (Codeigniter)

Newbie here. My target is to get the ID of the person that I'm going to transfer with. For example: His userID = 4. The userID in my database userID column should be = 4. I have provided screenshot below for better explanation. Thank you in advance

https://prnt.sc/w9piat << Screenshot of my problem and my target

Views:

<button data-id="<?php echo $rows->userID; ?>" class=" fundTable btn btn-success btn-sm text-bold " type="button"  data-toggle="modal" data-target="#fundModal">
  <i class="fas fa-hand-holding-usd mr-1"></i> <?php echo $rows->userID; ?>FUND
</button>

Controller:

public function form_validation()
    {
        $this->load->library('form_validation');
        $this->form_validation->set_rules("amount","Amount", 'required|numeric');
        
        if($this->form_validation->run())
        {
            
            $ref= $this->session->userdata('userID') + time ();
            
            
            $data = array(
                'userID' => $this->session->userdata('uid'),
                'transactionSource' => 'fund',
                'refNumber' => 'FI' . $ref,
                "amount" =>$this->input->post("amount"),
                "transType" =>"in",
                
                
            );
            $ref= $this->session->userdata('userID') + time ();
            
            $data1 = array(
                'userID' => $this->session->userdata('uid'),
                "transactionSource" => 'fund',
                "refNumber" => 'FO' . $ref,
                "amount" =>$this->input->post("amount"),
                "transType" =>"out",
                
                
            );
            
            
            $this->networks->insert_data($idata, $idata1);
            
          
            
            redirect(base_url() . "network/agents");
        }
        
        else
        {
            $this->index();
        }
        
    }

Model:

function insert_data($data,$data1)
    {
        

        
        $sql1 = "select * from transaction_ledger where userID = ?  order by ledgerID desc limit 0,1";
        $Q1 = $this->db->query($sql1, $data['userID']);
        
        $R1 = $Q1->row_array();
        $ref= $this->session->userdata('userID') + time ();
        
        $idata = array(
            'userID' => $data['userID'],
            'transactionSource' => 'Fund',
            'transType' => 'out',
            'refNumber' => 'FO' . $ref,
            'amount' => $data['amount'],
            'currentBalance' => $R1['currentBalance'] - $data['amount'],
            'previousBalance' => $R1['currentBalance'],
            
        );
        
        $this->db->insert('transaction_ledger', $idata);
        
       
        //update current wallet
        $sqlUpdate = "update users set currentPoints = '".$idata['currentBalance']."', dateUpdated = '".date('Y-m-d h:i:s')."'where userID = ?";
        
        $this->db->query($sqlUpdate, $data['userID']);
        
       
        
        //update you will get the fund
        
        
        
        $idata1 = array(
          //  'userID' => $data['userID'],  (My target is, the ID of the person that i will transfer the fund. How can i get his/her ID? 
            'transactionSource' => 'Fund',
            'transType' => 'in',
            'refNumber' => 'FI' . $ref,
            'amount' => $data['amount'],
            'currentBalance' => $R1['currentBalance'] + $data['amount'],
            'previousBalance' => $R1['currentBalance'],
            
        );
        $this->db->insert('transaction_ledger', $idata1);
        
        $sqlUpdate = "update users set currentPoints = '".$idata1['currentBalance']."', dateUpdated = '".date('Y-m-d h:i:s')."'where userID=0";
        
        $this->db->query($sqlUpdate, $data['userID']);
    }
       

}