Have you contacted Customer Support through this form and asked for the Pass Cover Number?

https://eurail.zendesk.com/hc/en-001/requests/new

Customer Support is currently overloaded with requests so you will probably have to be patient to get help. If you are currently travelling or will be travelling in the next weeks you should inform Customer Support about that.

For most routes there are different possibilities to make reservations and some don't require the Pass Cover Number.

If you write what reservations you want to make, hopefully you can get advice on how to reserve without the Pass Cover Number

Hi I am also trying to book reservation London but to Amsterdam. I need my pass cover number for my mobile pass to make a reservation. Thanks

Thanks @AnnaB They were able to sort out the cover Pass Cover number very quickly

@Alunjudithlewis

You need to contacted Customer Support through this form and asked for the Pass Cover Number.

https://eurail.zendesk.com/hc/en-001/requests/new

Customer Support is currently overloaded with requests so you will probably have to be patient to get help. If you are currently travelling or will be travelling in the next weeks you should inform Customer Support about that.