For your product category ID 64, the following code will replace add to cart button by a custom button in single product pages and by a linked button to the product on archives pages:
// The custom replacement button function
function custom_product_button(){
    // HERE your custom button text and link
    $button_text = __( "Custom text", "woocommerce" );
    $button_link = '#';
    
    // Display button
    echo '<a class="button" href="'.$button_link.'">' . $button_text . '</a>';
}
// Replacing the single product button add to cart by a custom button for a specific product category
add_action( 'woocommerce_single_product_summary', 'replace_single_add_to_cart_button', 1 );
function replace_single_add_to_cart_button() {
    global $product;
    
    // Only for product category ID 64
    if( has_term( '64', 'product_cat', $product->get_id() ) ){
        // For variable product types (keeping attribute select fields)
        if( $product->is_type( 'variable' ) ) {
            remove_action( 'woocommerce_single_variation', 'woocommerce_single_variation_add_to_cart_button', 20 );
            add_action( 'woocommerce_single_variation', 'custom_product_button', 20 );
        }
        // For all other product types
        else {
            remove_action( 'woocommerce_single_product_summary', 'woocommerce_template_single_add_to_cart', 30 );
            add_action( 'woocommerce_single_product_summary', 'custom_product_button', 30 );
        }
    }
}
// Replacing the button add to cart by a link to the product in Shop and archives pages for as specific product category
add_filter( 'woocommerce_loop_add_to_cart_link', 'replace_loop_add_to_cart_button', 10, 2 );
function replace_loop_add_to_cart_button( $button, $product  ) {
    // Only for product category ID 64
    if( has_term( '64', 'product_cat', $product->get_id() ) ){
        $button_text = __( "View product", "woocommerce" );
        $button = '<a class="button" href="' . $product->get_permalink() . '">' . $button_text . '</a>';
    }
    return $button;
}
Code goes in function.php file of your active child theme (or theme).
Tested and works.