Have you been getting IRS notices each year in the past containing your IP PIN? If so, you should be getting one by that method again this year to be used for any returns filed during calendar year 2025. The IRS website, from what I've found, says that the CP01A letter goes out "December/January." So it's likely that some people are just now getting theirs. But I'll mention a faster way you may be able to get it below.
Not everyone in the IP PIN program will get an IRS notice CP01A with their 2025 IP PIN. That notice typically goes to those in the IP PIN program who experienced tax-related identity theft that was examined by the IRS. Filers who opted-in to the IP PIN program don't typically get a letter. The fastest way for most people in both groups to see their 2025 IP PIN is to sign into one's online IRS account. The IRS now displays the IP PIN within that account.