I would like to but I have no idea what to write in it. Also, based on previous interaction with my DPO at the time of the reddit fiasco (and if I’m not mistaken as per the GDPR) I first have to attempt to contact the entity holding my data before filling in a complaint form. Furthermore as I have stated in another comment, I have completely lost faith in my country’s DPO after having to go through them for reddit’s non-compliance with the GDPR, and honestly believe they are just incompetent and don’t fully understand the laws their entire position was created to defend.