Codeigniter中有多个相同的表单

I have a view that shows all the extensions made by student. It lists all the extensions in a form type to easily update it and just hit submit.

These forms are inside a for loop. This is my view code.

<?php for ($x=0; $x<count($param_visa_extensions); $x++) { ?>
    <div class="row p-b-10 p-t-20 border-bottom <?php if ($x==0) { echo 'entry'; }?>">
        <form action="<?php echo base_url('dashboard/staff/admin/insert_extension'); ?>" method="post">
            <div class="row">
                <input type="hidden" name="form-visa-id" id="form-visa-id" value="<?php echo $param_visa_extensions[$x]->visa_idx; ?>" />
                <div class="col-md-3">
                    <div class="form-group">
                        <label class="text-danger"><?php echo ('Order') ?></label>
                        <select class="form-control select-order" name="form-extension-order" required />
                            <option value=""></option>
                            <option value="1" <?php if ($param_visa_extensions[$x]->order_no == 1) { echo 'selected';} ?>>1st</option>
                            <option value="2" <?php if ($param_visa_extensions[$x]->order_no == 2) { echo 'selected';} ?>>2nd</option>
                            <option value="3" <?php if ($param_visa_extensions[$x]->order_no == 3) { echo 'selected';} ?>>3rd</option>
                            //and so on
                        </select>
                    </div>
                </div>
                <div class="col-md-3">
                    <div class="form-group">
                        <label class="text-danger"><?php echo ('Period') ?></label>
                        <select class="form-control" name="form-extension-period" required />
                            <option value=""></option>
                            <option value="1" <?php if ($param_visa_extensions[$x]->period == 1) { echo 'selected';} ?>>1 month</option>
                            <option value="2" <?php if ($param_visa_extensions[$x]->period == 2) { echo 'selected';} ?>>2 months</option>
                            <option value="3" <?php if ($param_visa_extensions[$x]->period == 3) { echo 'selected';} ?>>3 months</option>
                            //and so on
                        </select>
                    </div>
                </div>
                <div class="col-md-3">
                    <div class="form-group">
                        <label class="text-danger"><?php echo ('Start') ?></label>
                        <input class="form-control mdate" type="text" name="form-extension-start" value="<?php echo $param_visa_extensions[$x]->start_date?>" required />
                    </div>
                </div>
                <div class="col-md-3">
                    <div class="form-group">
                        <label class="text-danger"><?php echo ('End') ?></label>
                        <input class="form-control mdate" type="text" name="form-extension-end" value="<?php echo $param_visa_extensions[$x]->expiration_date?>" required />
                    </div>
                </div>  
                <div class="col-md-2">
                    <div class="form-group">
                        <div class="custom-control custom-checkbox">
                            <input type="checkbox" class="custom-control-input" id="acr-checkbox<?php echo $param_visa_extensions[$x]->idx; ?>" data-for="form-extension-acr" data-val="YES" <?php if ($param_visa_extensions[$x]->acr == 'YES') { echo 'checked';} ?> />
                            <label class="custom-control-label text-danger" for="acr-checkbox<?php echo $param_visa_extensions[$x]->idx; ?>">I-CARD</label>
                        </div>
                    </div>
                </div>
                <div class="col-md-3">
                    <div class="form-group">
                        <label class="text-danger"><?php echo ('Amount') ?></label>
                        <div class="input-group">
                            <div class="input-group-prepend">
                                <span class="input-group-text">₱</span>
                            </div>
                            <input class="form-control" type="number" name="form-extension-amount" value="<?php echo $param_visa_extensions[$x]->amount?>" required />
                        </div>
                    </div>
                </div>
                <div class="col-md-7">
                    <div class="form-group">
                        <label class="text-danger"><?php echo ('Remarks') ?></label>
                        <textarea class="form-control" name="form-extension-remark" rows="3" maxlength="128" required=""><?php echo $param_visa_extensions[$x]->remarks?></textarea>
                    </div>
                </div>  
                <div class="col-md-2 button-div" style="display: none;">
                    <div class="form-group">
                        <button class="btn btn-block btn-add btn-add-per-row" ><i class="fa fa-plus"></i></button>
                    </div>
                </div>
                <div class="col-md-2">
                    <div class="form-group">
                        <button type="submit" class="btn btn-info btn-rounded"><i class="fa fa-magic"></i> &nbsp; S U B M I T</button>
                    </div>
                </div>  
            </div>
        </form>             
    </div>
<?php } ?>

How do I make it that it takes each row as a unique form but only using one function in the controller for the submit?