Issue with NI post delivery

I applied for NI number on February 1 and haven't received it via post till now. 3 weeks ago, I called the National insurance helpline and they confirmed that it has been issued and generated a new letter. However, I didn't receive it still. I reached out to the National insurance helpline today to figure out what the issue was, and they mentioned that Royal mail had an issue with the delivery and returned the letter. I am currently at a new address and need to post a new letter again, but I was told to reach out to HMRC to update this first. Can the team help?

Hi Adeola Adeyemo,
If wish to change your address you can do this via you PTA (Personal tax account) Personal tax account: sign in or set up or they can call our NI helpline and after passing security we can update their record with new information.
Thank you.