Theme Earth Pro

Hello,
in the theme Earth Pro, I would like to see only posts that are in same category
I explain :
in this page :
https://www.a-picture-from-switzerland.com/?p=239

I have at the end some links that are posts and I like it this way, BUT I can go to all the posts of the website and I only want to be able to read the post of the same category in my example “Nettoyage”
Hope someone can help me, is there any way to do this.
a plugin or a pho change

fo what I have understand, the theme have a php page that contain something about navigation. maybe there is a line to change to indicate navigation in the actual catégory ?

if ( ! function_exists( ‘earthpro_paging_nav’ ) ) :
/**
* Display navigation to next/previous set of posts when applicable.
*/
function earthpro_paging_nav() {
// Don’t print empty markup if there’s only one page.
if ( $GLOBALS[‘wp_query’]->max_num_pages < 2 ) {
return;
}
?>
<nav class=”navigation paging-navigation” role=”navigation”>
<h1 class=”screen-reader-text”><?php _e( ‘Posts navigation’, ‘earthpro’ ); ?></h1>
<div class=”nav-links”>

<?php if ( get_next_posts_link() ) : ?>
<div class=”nav-previous”><?php next_posts_link( __( ‘<span class=”meta-nav”>←</span> Older posts’, ‘earthpro’ ) ); ?></div>
<?php endif; ?>

<?php if ( get_previous_posts_link() ) : ?>
<div class=”nav-next”><?php previous_posts_link( __( ‘Newer posts <span class=”meta-nav”>→</span>’, ‘earthpro’ ) ); ?></div>
<?php endif; ?>

</div><!– .nav-links –>
</nav><!– .navigation –>
<?php
}
endif;

if ( ! function_exists( ‘earthpro_post_nav’ ) ) :
/**
* Display navigation to next/previous post when applicable.
*/
function earthpro_post_nav() {
// Don’t print empty markup if there’s nowhere to navigate.
$previous = ( is_attachment() ) ? get_post( get_post()->post_parent ) : get_adjacent_post( false, ”, true );
$next = get_adjacent_post( false, ”, false );

if ( ! $next && ! $previous ) {
return;
}
?>
<nav class=”navigation post-navigation” role=”navigation”>
<h1 class=”screen-reader-text”><?php _e( ‘Post navigation’, ‘earthpro’ ); ?></h1>
<div class=”nav-links”>
<?php
previous_post_link( ‘<div class=”nav-previous”>%link</div>’, _x( ‘<span class=”meta-nav”>←</span> %title’, ‘Previous post link’, ‘earthpro’ ) );
next_post_link( ‘<div class=”nav-next”>%link</div>’, _x( ‘%title <span class=”meta-nav”>→</span>’, ‘Next post link’, ‘earthpro’ ) );
?>
</div><!– .nav-links –>
</nav><!– .navigation –>
<?php
}
endif;