Tag "read more" not working

[fullframecreative]

Hello Phil,

My client gave me a text to put on his the website but the text is enormous. So I would like to use the Tag

<!--more-->

to only show the first paragraph and then if the person would like to continue to read would click on the button to show the rest of the text.
Unfortunately, no matter what I try the tag never works!

Can you help me with this problem please?
I’ll include some print screens and additional information in the comment below.

Thank you in advance.
Nuno

Ticket