The new Android 12 with Samsung One Ui 4 is just coming out of Beta and is being sent out to some of Samsungs Flagship phones @zimma71 with after a period of time then being sent out to more eligible phones.
There is some good initial information on sammobile.com
In regards to how you download this update it should show up as an available download in your phones settings , software update section. You can set the phone to automatically download it and you can perform a software search in that section too.
Some owners elect to use Samsung Smartswitch to search for the update.
You maybe looking at some point early next year if the update becomes available for your phone, but dont hold me to that particular timeline
Current Phone > Samsung Z Fold³ 5G. > Software : Android 12 ~ Samsung One Ui 4.