I don't think IBKR offers IPO. In any case, IPO allocation are handled by underwriters, unless you are a very good client, most likely you won't get a good price for hot stocks.
There are no IPOs for US listing to my understanding. I have key account services (large account), and have had the subscribe to IPOs selected for years, never a single opportunity for any US listings.
If you have decent money with a broker/bank, like a private bank client who retail trades, you often could get in on IPOs, probably not huge allocations or the huge oversubscribed ones, but have gotten allocations in the past.