Bulleted list item
Create empty item
php
$item = BulletedListItem::create();
Create from string
Bulleted list items can be created from simple strings.
php
$item = BulletedListItem::fromString("Item content");
Create from RichText 
php
$text = RichText::fromString("Item text")->italic();
$item = BulletedListItem::create()->changeText($text);
Add text
php
$item = BulletedListItem::fromString("Item text");
$item = $item->addText(
    RichText::fromString(" can be extended!")
);
echo $item->toString();
Output:
Item text can be extended!
Add child
php
$item = BulletedListItem::fromString("Item text");
$item = $item->addChild(
    Paragraph::fromString("A simple child paragraph.")
);

Change children
php
$item = BulletedListItem::fromString("Item text")
    ->addChild(Paragraph::fromString("Old child"));
$item = $item->changeChildren(
    Paragraph::fromString("Child paragraph 1"),
    Paragraph::fromString("Child paragraph 2"),
);

Convert to string
Get item content as string
php
$item = BulletedListItem::fromString("Item text");
echo $item->toString();
Output:
Item text
Notion SDK PHP