[WP] How to upload different image sizes?

Question

Web development

Tell me how to make it so that different image sizes are loaded on WP.
Specifically, you need to make sure that when adding to a record, only one file is created, and when adding a thumbnail, 4 files of different sizes are created.

Answer 1

In functions.php

add_image_size( 'thumb1', 220, 180,true );
add_image_size( 'thumb2', 220, 180,true );
add_image_size( 'thumb3', 220, 180,true );
add_image_size( 'thumb4', 220, 180,true );