Visibility of a local variable

A local variable, created within a transaction, continues to persist
(without value) after the transaction has ended.

> select version();
PostgreSQL 12.15 (Ubuntu 12.15-1.pgdg18.04+1) on x86_64-pc-linux-gnu,
compiled by gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0, 64-bit

> select current_setting('my.var1');
ERROR: parámetro de configuración «my.var1» no reconocido SQL state: 42704
(as expected)

> begin;
> set local my.var1 = true;
> commit;
(everything ok)

> select current_setting('my.var1');
returns an empty field (current_setting)

It should return the same error as in the first statement

Greetings, Alejandro