For a return from France, the package must be dropped off at a Colissimo drop-off point or a post office.
You can follow this link to find the nearest drop-off points: https://www.laposte.fr/particulier/outils/trouver-un-point-de-retrait-ou-de-depot-colissimo
Returns from Belgium, Germany, Austria, Croatia, Denmark, Spain, Estonia, Hungary, Lithuania, Luxembourg, the Netherlands, Poland, Portugal, Slovakia, Slovenia, Sweden, and Latvia must be dropped off at a DPD drop-off point. Here is the link to find the nearest drop-off locations: https://www.dpd.com/be/fr/
Returns from Greece, Romania, Italy, Ireland, Bulgaria, and Malta must be dropped off at a local post office.
Returns from Andorra, Cyprus, Switzerland, Réunion, and Australia must be sent via DHL.
Here is the link to find the nearest drop-off points: https://locator.dhl.com/?l=en&countryCode=fr