Expandanble text field..."read more" button

Hi there,

I have been trying to follow a step by step process as to how to add the right code to create the above. Im getting through it and experiencing a problem when the tutorial wants me to rename the “dynamicDataset” part of the code…

I do not necessarily know of the page is a dynamic page…

I only want to decrease the amount of text shown on the page (without deleting… obv) with a “read more” button placed below that will expand the text field revealing the rest of the text.

Any help would be greatly appreciated.
Thanks