Current regulations for selling in europe are quite exhaustive in terms of product safety but don’t specifically cover drones. The classes I have previously covered fills that gap and will form part of the requirements to CE mark drones to be sold in the EU. The following are the responsibilities of the Manufacturer in respect to drones they sell:

Ensure software, design or characteristic changes are only be issued if they don’t affect compliance with the DR
Ensure compliance with the DR, provide technical information and conformity assessment
Produce Declaration of Conformity and CE Marking and they should keep this for 10 years
Put procedures in place to ensure series production remain compliant
Ensure drone / remote ID add on has the type/class (drone only) and unique serial number
Provide trading name, address, website etc on product, packaging or accompanying documentation
Ensure product has User Manual and EASA Information notice in language that can be understood
Take corrective actions when known to not be compliant and respond to audits
They may delegate certain aspects of this to an Authorised Representative (i.e. data retention, audits, and/or non-conformity actions).

Small Print: These posts are a summary only, include my personal interpretation and are not intended to be a replacement for reading the actual rules.