Upstreaming code changes using custom CLA

Hi,

I want to upstream a few code changes to Couchbase and its components, however I cannot sign the CLA which is presented at review.couchbase.org >> settings >> Agreements.
This is because my organization has a custom CLA signed with Couchbase. Could somebody please advise me how I can use custom CLA instead of generic CLA?

Thanks,
Atul.