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.

@brins  I have answered your message :) 

@Magdalena thanks, could you please reply to my second message

Hi,

I need Eurail cover pass numbers for the 2 mobile Eurail passes purchased through RailEurope website. This is required for Eurostar booking. I request  @Magdalena

through private message about an hour back, still waiting for it. Can someone help please? 

Thanks, Samit

You asked here just one hour ago The Community Supervisors like Magdalena are humans like you and work usually due standard office hours (CET) because of that you may wait one day or two days. 
 

Hi ,

I did not receive the response yet. Can you please expedite?

Samit

Maybe she wasn´t online yet .

Did you open a case on the via the serviceform?
https://eurail.zendesk.com/hc/en-001/requests/new

It is almost midnight here in Europe and the Eurail staff that are members of the community are working normal CET office hours, thus Magdalena will most likely not be working until Monday.

Thats fine if I receive a response by Monday.

Tried, but no luck

You can generate a pass cover number here without having to contact customer service:

https://www.eurail.com/en/book-reservations#/generatePassCoverNumber?utm_source=chatbot&utm_campaign=pcn
You can access this by using the chat bot on the help page by typing pass cover number.