Indeed, the Partner declarations can only be generated after the submission of your application, and need to be provided before project approval. Same applies to De Minimis (only for concerned partners).
The deadline set for uploading such documents is the 10th November, however the submission of the documents is not a question of eligibility anymore, so if they are still missing by this deadline, they can be added in the following days. If some are still missing at the time of project approval, they will be requested as a formal condition for approval (before signature of the subsidy contract).