Hey @jeremy98
Based on some old article it looks it cannot be done:
There are a few caveats you should keep in mind when adopting this new feature. Identity columns cannot be added to existing tables; the tables will need to be recreated with the new identity column added. To do this, simply create a new table DDL with the identity column, and insert the existing columns into the new table, and surrogate keys will be generated for the new table.
I think recreate and copy data will be the ea