Add a Code Block (Cursor at the insert point and press +). Then add the code.
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Centre text in a code block: <center> text here <center>
Bold text in a code block: <b> text here <b>
Italics in a code block: <i>
Red text in a code block: <span style="color:#FF0101"><p> text here </p><span style="color:#FF0101">
Subscript in a code block: <sub> text here <sub>
Superscript in a code block: <sup> text here <sup>