Resize post thumbnail

Why don’t you use this add_image_size( 'custom-thumbnail', 300, 300, true ); in funtions.php

and call it <img src="<?php echo get_the_post_thumbnail_url('custom-thumbnail'); ?>"> in your page?

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)