One of the key principles behind copyright is ownership and allowing an original creator to maintain control over where and how their work is displayed, distributed, reproduced, and so on. Linking to content through a hyperlink or QR code to send a TpT’er directly to the source rather than copying and pasting that content into your resource tends to be a much safer option.
That being said, the law on this issue is pretty murky, and some website owners have adopted what’s called “no link” policies. So, it’s good practice to be aware of whether the site you want to link to has any restrictions like this, or ask for permission to link to the content you’re interested in.
If you provide hyperlinks or QR codes in your TpT products, it will be up to you to make sure that your linked resources are current and accessible. If the links are outdated or the content has been removed from the system you linked to, we may have to issue a refund to your Buyer and deactivate your product.