@Volanaro Android 13 should come in due course once testing is complete as @Glenntech has explained. If too long a delay there is the option to see if is available via Smart Switch, need to connect device to computer and have the latest software installed. Some information here https://seektogeek.com/how-to-update-any-samsung-phone-to-latest-software/
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.0,Android 13 .