Параметры форматирования в элементе textArea в Angular Material

You can't do that but there is another way. delete the textarea.use contenteditable = "true".using contenteditable = "true" you can edit in your textarea section.

'<section id = "textarea" contenteditable = "true">
<ul>
    <li>List item here</li>
    <li>List item here</li>
    <li>List item here</li>
    <li>List item here</li>
</ul>

</section>'