Cannot receive my UTR number

I submitted the Self Assessment form by online on 16 Sep 2024, but I still cannot get the UTR number. This is my first tax return and need to apply for split year allowance. Could you let me know the status of it?

Hi,
To find your UTR you can:
Sign in to your personal tax account:
Personal tax account: sign in or set upYou can also find your Unique Taxpayer Reference on:

• Previous tax returns
• Emails from HMRC
• Other documents HMRC has sent you

Your UTR is a 10-digit number and may also be called 'tax reference'.
If you've already registered for Self Assessment you can find out when you should receive your UTR:
Check when you can expect a reply from HMRC
Thank you