Indeed, Stripe very often requires more documents from providers (IDs like passports, proof of where they live, …). Accounts are restricted until documents are provided.
Sellers can simply visit their payment details page and they’ll see a note there if there is something that should be updated. They can then simply upload the required documents from the payment details form. This happens in their user settings: from the top bar, hover on the profile picture then Settings, then Payments. Once uploaded, Stripe usually verifies the documents automatically within seconds, but sometimes needs a manual review and approves them only after a few hours. Once everything is set, the message in the Payments section confirms that it’s all set.
It’s a good idea for you to monitor, from your Stripe dashboard, restricted accounts, and follow up with your members to let them know that they won’t be able to receive any money until they’ve provided the documents.