The Notices section in my Samsung Members App shows that model was completed for the update direct from Samsung on the 21st April 2021.
Best practice is to keep periodically manually checking via your phone's software update section and or turn on automatic auto download over Wi-Fi.
The software updates are sent out via Samsung Servers dependent on the phone's serial number, build number, region.
And sometimes if the phone is branded i.e locked to a network or unbranded i.e unlocked to all networks this can delay things as sometimes a network wants to test the firmware before it's sent out to their branded phone's.
You could look at sammobile.com and xdadevelopers.com to look at available custom rom's however you must also make yourself aware of the potential pitfalls of following this route @thehappylemon
Disclaimer 》 Using a Custom Rom / trying to use other methods to rollback firmware can bring about an unstable phone or it may not work properly if the process glitches or the wrong Rom is used. It may stop Samsung Pay from working if the procedure trips your Knox Counter.A person takes full responsibility if they perform this process and do so at their own informed decision. Again the process may trip Knox and may affect the Samsung Warranty. Samsung could levy a charge to put this right or deny support.
Personally I'd advise to wait for an eligible update to reach your phone and not run the risk of destabilising the phone.
A Samsung Experience Store or Samsung Service Centre might be able to help.