Expandable WordPress content (text) inside a post

Question

I've created a CPT in my WordPress site. In this CPT I have the content element (which is the default WP content) and want to make it expandable, I mean, while viewing the CPT I want it to only display a few lines of text until you press the view full content or something similar, all this inside the post view. Like in the image below:

Answer 1

There might be two reasons for your problem

1. You are using <!--more--> tag inside your content . If so then remove it.
2. While querying post you are using the_excerpt method , if so then change it to the_content .

Answer 2

I solved it using the following WordPress Plugin, which has plenty of options to customize: https://wordpress.org/plugins/jquery-collapse-o-matic/