How to properly use Pjax for links?

Question

Yii

Good day. There is a page where you need to accept applications from users or reject them.
view:

<?php foreach ($members as $member): ?>
    <?php if(($project->id == $member->project_id) && $member->status == 1): ?>
        <?php Pjax::begin(); ?>
                <?= $this->render('_waitmember', [
                    'project' => $project,
                    'member' => $member,
                ]) ?>
        <?php Pjax::end(); ?>
    <?php endif; ?>
<?php endforeach; ?>

_waitmember:

<li><?= $member->user->username; ?></li>
<a class="btn btn-success" 
    href="<?= Url::to(['projects/accept', 'id' => $member->user->id, 'project_id' => $project->id]) ?>"
    data-method="post" data-pjax="1">Принять
</a>
<a class="btn btn-danger" 
    href="<?= Url::to(['projects/reject', 'id' => $member->user->id, 'project_id' => $project->id]) ?>"
    data-method="post" data-pjax="1">Отклонить
</a>

controller:

public function actionAccept($id, $project_id)
    {
        $project = $this->findProject($project_id);
        $member = $project->isWaitingMember($id);

        if($member) {
            $member->status = 2;
            $member->save();
        }

        return $this->renderAjax('_waitmember', [
            'project' => $project,
            'member' => $member,
        ]);
    }

It looks like this:

The problem is that when you click on the "Accept" or "Reject" button, actions with the database occur as needed, but the block itself with the username and buttons remains.
Where could be the error or how can it be fixed?
Thanks in advance.