Possible Example Error in Documentation

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/12/plpgsql-transactions.html
Description:

We are using Postgres 12. When I use the example given for
transaction_test1() from the documentation here:
https://www.postgresql.org/account/comments/new/12/plpgsql-transactions.html/,
the procedure is created without incident. However, when I attempt "CALL
transaction_test1();", I receive the "invalid transaction termination"
error.

Please correct the documentation if the example is flawed, or add an
explanation on the page if we need to set specific environment variables.

Thank you.