That’s excellent news that you’re due a rebate!
That’s correct, if you didn’t include bank details for HMRC then they’ll issue a cheque. Typically, this will be sent a month or two after your return is submitted. However, processing time will depend on when you send your return in and how big a backlog they’re currently experiencing.
You can get an idea of when to expect this using their online tool here.
All the best,