Remove Shop title storefront theme

I’ve created a child theme called storefront-child, it works fine. I need to remove the Page title for the shop page. I have my Caching plugin turned off.

I have tried adding this to the CSS with no change.
.woocommerce-products-header__title page-title {display: none;}

I have added the code from here: https://wordpress.org/support/topic/remove-shop-page-title-2/ to a functions.php file in my child theme folder. I get an error. Am I supposed to put this code in some other file?

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