Addition of encrypted fields to existing schema when using Queryable encryption

We’re using Automatic Queryable encryption to encrypt PII data of our users.
I have already created an encrypted collection called users with certain fields like firstName, lastName, phoneNumber by making the call clientEncryption.createEncryptedCollection and passing encryptedFieldsMap with the above mentioned fields.
Everything is working fine including encryption and decryption.
Now, I would like to encrypt a new field called ssn in the existing collection.
I don’t see a helper method like clientEncryption.updateEncryptedCollection in the ClientEncryption object.
How should I proceed with addition of new encrypted field in existing collection ?
Any help would be appreciated.

Unfortunately we don’t support adding new fields to an encrypted collection at this time. My understanding is that the reason behind this is because we don’t create the new structured metadata in the database that would be required to support it. The best we have now is to create a new encrypted collection with the new field and use mongosync to migrate the data over.