Congrats on your new born
I am guessing you have send the info regarding your baby through a web form, if not please do so.
Regarding calling IRCC, I haven't heard anyone has managed to call them recently. Personally, I prefer not to, as IRCC agents like us have been through rough times, let's try to be kind to them and be a little more patient.
I am sure in no time you will hear from them. Fingers crossed!