How to create different thumb size for different post type.php

<?php

add_action( 'pre-upload-ui', 'get_the_post_type' );
function get_the_post_type() {
    $post_type = isset( $_REQUEST['post_type'] ) ? $_REQUEST['post_type'] : 'post';
    set_transient( 'attached_post_type', $post_type );
}

add_filter( 'intermediate_image_sizes_advanced', 'add_image_size_for_post_type', 10 );
function add_image_size_for_post_type( $sizes ) {
    $post_type = get_transient( 'attached_post_type' );
    delete_transient( 'attached_post_type' );
    
    /*
     * BLOCK A
     *
     * This can be used if you want to set different size for only one post type. For multiple post type, check BLOCK B
     *
     */
    if( $post_type == 'page' ){
	    $sizes['post-thumbnail'] = array( 'width' => 275, 'height' => 175, 'crop' => true );
    }
    // END OF BLOCK A
    
    
    /*
     * BLOCK B
     *
     * This can be used if you want to set different sizes for different post types.
     *
     */
    $post_type_size = array(
			    'post' => array( 'width' => 275, 'height' => 175, 'crop' => true ),
			    'page' => array( 'width' => 375, 'height' => 475, 'crop' => true ),
			    'CPT' => array( 'width' => 475, 'height' => 675, 'crop' => true )
			    );
    
    if( isset( $post_type_size[$post_type] ) ) $sizes['post-thumbnail'] = $post_type_size[$post_type];
    
    // END OF BLOCK B

    return $sizes;

}