How to get a product attribute by name using WC_Product->get_attribute( 'brand' ) and link to attribute archive.

woocommerce-get-brand-name.php

<?php
// Put the product's brand and link to archive above product title on single_product page.
add_action( 'woocommerce_single_product_summary', 'msp_brand_name', 1 );

// Put same link on shop page
add_action( 'woocommerce_before_shop_loop_item_title', 'msp_brand_name', 15 );

function msp_brand_name(){
    /**
     * Get the product's brand name and link to brand archive
     */
    global $product;
  
    // You dont need the 'pa_' prefix. Insert the slug for the product attribute you want.
    $brand_slug = 'brand';
  
    $brand = $product->get_attribute( $brand_slug );
    
    // Nothing? STOP.
    if( empty( $brand ) ) return;

    // If we get this far, we found a brand. (Dont remove the pa_)
    $term = get_term_by( 'name', $brand, 'pa_' . $brand_slug );
    
    // Not an archive.
    if( $term === false ){
        printf( '<div class="product-brand"><span>%s</span></div>', $brand );
    } else {
    // Found link - is an archive.
        $link = get_term_link( $term->term_id );
        printf( '<div class="product-brand"><a href="%s">%s</a></div>', $link, $brand );
    }
}