Steps to add custom preoder label to all the products of a collection:
- Go to “Online Store” → “Themes”.
- Click action button from the current theme and select “Edit code”.
- Locate the file “card-product.liquid” and search class named “card__badge”.
- Add the below code
{%- if card_product.tags contains 'pre-order' and card_product.available -%}
{%- endif -%}
hopefully you will get that what you need.