Disable unique SKU in woocommerce productd

Hello everybody

Can anybody assist me with getting a code snippet to work?
Through a ticket on woocommerce i received the below code.
add_filter( ‘wc_product_has_unique_sku’, ‘__return_false’, PHP_INT_MAX );

I figured i put it in my theme’s function.php
But doesn’t seem to work.
The idea is to be able to import products databases(csv) which use the same SKU’s for different products.
So basically disable unique SKU, i don’t want to remove it just disable the check so it doesn’t skip them during the import due to duplicate SKU.

Thanks