How to get all posts related to particular category name on button click?

How to get category wise all post in WordPress?

Add below code in taxonomy-“yourtaxonomyname”.php

for ex : file name : taxonomy-event-category.php & Post type : events & taxonomy name : event-category

<?php
$category_object        = get_queried_object();
$category_taxonomy      = $category_object->taxonomy;
$category_term_id       = $category_object->term_id;
$category_name          = $category_object->name;
$category_description   = $category_object->description;
$category_slug          = $category_object->slug;

$post_type="events";
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$post_args=array(
    'type'                     => $post_type,
    'post_status'              => 'publish',
    'posts_per_page'           => 15,
    'paged'                    => $paged, 
    'caller_get_posts'         => -1,
    'child_of'                 => 0,
    'parent'                   => 0,
    'orderby'                  => 'name', 
    'order'                    => 'ASC',
    'hide_empty'               => 0,
    'hierarchical'             => 1,
    'exclude'                  => '',
    'include'                  => '',
    'number'                   => '',
    'tax_query'                => array(
                                        array(
                                            'taxonomy' => $category_taxonomy,
                                            'field' => 'id',
                                            'terms' => $category_term_id
                                        )
                                    ),
    'pad_counts'               => false, 
);
$post_my_query = null;
$post_my_query = new WP_Query($post_args);

if( $post_my_query->have_posts() ) :
?>

    <ul>
        <?php
            while ($post_my_query->have_posts()) : $post_my_query->the_post(); 
            ?>
            <li>
                <a href="https://wordpress.stackexchange.com/questions/282963/<?php echo get_permalink($post->ID);?>">
                <?php
                    if ( has_post_thumbnail() ) {
                        //get_the_post_thumbnail( $post->ID, array( 100, 100) ); 
                       ?>
                        <?php echo  get_the_post_thumbnail($post->ID,'medium'); //thumbnail,medium,large,full,array(100,100)?>
                       <?php
                    }
                ?>
                    <p><?php echo get_the_title( $post->ID );?></p>
                </a>
            </li>
            <?php
           endwhile;
       ?>
    </ul>

<?php
else :      
    echo '<p class="red-error">No Post Found!</p>'; 
endif;

wp_reset_query($post_my_query);
?>
<?php //if(function_exists('wp_pagenavi')) { wp_pagenavi( array( 'query' => $post_my_query ) ); }else{ echo '<p class="red-error">No Event Post Found!</p>'; }
?>