As with reMarkable desktop's app, you need to allow your reMarkable account to receive documents from this platform.
To do that, you need to copy your one-time code and paste it below:
The one-time code does not have the correct format (8 characters).
And please, enter an email address (gmail, hotmail...) so that you can create your account in the future to manage your subscriptions:
You have to enter a correct email address.