Woocommmerce Product Template not working

Good morning, I am trying to customize the product page by creating a new template. I’m attempting to use one of the existing WooCommerce templates following the instructions in the video https://statics.teams.cdn.office.net/evergreen-assets/safelinks/2/atp-safelinks.html, but when I follow the procedure, it doesn’t load the template—it only shows a blank page.