'Next/Previous article' inside the Article

https://codex.www.ads-software.com/Function_Reference/next_post_link
https://codex.www.ads-software.com/Function_Reference/previous_post_link

can You please help me with this too:
I decided to include the
‘Text As Link, Without Post Title, Within Same Category‘,
where should I add this code now:
<?php next_post_link(‘%link’, ‘Next post in category’, TRUE); ?>

BackY,

Can you elaborate on the second question a little more. What are you expecting to happen here?

I red the instructions from the link.
There were different options on what to insert as ‘next’ at the end of the post.

I choose the ”Text As Link, Without Post Title, Within Same Category’,’.
How can I add it to my articles now !? I need some hand.