For Posts after using an excerpt to display the remainer text

Help
1

For a long post I want to use the excerpt tag to only show XXX words. Then with a link in the post just before the end of the excerpt display the remainer of the post (Wordpress does this BTW). After working for multiple hours and attempts I cannot get it to work. I don’t use any theme.

I get the excerpt post fine but every type of link using different techniques I only get the same post . I cannnot find a sample code that does this

2

Can you provide an example, or even screenshots to clarify this? I didn’t understand what you are trying to achieve.