It is very clear from the GPSR page what the requirements are

You must then label those products with the contact information of the manufacturer and Responsible Person, and, if applicable, of the importer, including the postal and electronic address, in one of the EU’s official languages. Where the manufacturer and importer’s addresses are different, you must also include the postal or electronic address of the single contact point at which they can be contacted.

The labelling with the Responsible Person or importer information can be attached to the product, its packaging, the parcel or an accompanying document. However, the labelling with the manufacturer information must be placed on the product, and only if that isn’t possible can you place it on the packaging or in a document accompanying the product. If you’re using a QR code, you must also print the information in text form.