psql: generated by default as identity

Question

I'm following a psql tutorial on generating a table. However, I kept getting syntax error, even though I pasted in the exact code.

thisdb=# create table t1 (a int generated by default as identity, b int);
ERROR:  syntax error at or near "generated"
LINE 1: create table t1 (a int generated by default as identity, b i...
                               ^