[postgres-13@yz219 ~]$ psql test
test=# select * from pg_user;
   usename   | usesysid | usecreatedb | usesuper | userepl | usebypassrls |  passwd  | valuntil |             useconfig              
-------------+----------+-------------+----------+---------+--------------+----------+----------+------------------------------------
 postgres-13 |       10 | t           | t        | t       | t            | ******** |          | 
(1 rows)

test=# create user yz;
CREATE ROLE
test=# select * from pg_user;
   usename   | usesysid | usecreatedb | usesuper | userepl | usebypassrls |  passwd  | valuntil |             useconfig              
-------------+----------+-------------+----------+---------+--------------+----------+----------+------------------------------------
 postgres-13 |       10 | t           | t        | t       | t            | ******** |          | 
 yz          |    24643 | f           | f        | f       | f            | ******** |          | 
(2 rows)

[postgres-13@yz219 ~]$ psql test -U yz
psql (13.2)
Type "help" for help.

test=> create table t(a int);
test=> \q

[postgres-13@yz219 ~]$ psql test
test=# revoke select on t from yz;
REVOKE