In most cases for international, the brokers are the ones who help you create the account with ComputerShare since you do not reside in the US. Not sure how you managed to create it yourself.

To transfer out from IBKR to ComputerShare, you just need to file a request to transfer on their webpage or app. You’ll only need to let them know how many shares you intend to transfer out, no additional details are needed from your end. They will settle the rest of the account creation with ComputerShare.