How to use sieve_env_ variables in 2.4.4?

Hi Dear Devs!

In the previous version 2.3.x I used variables with the **sieve_env_** prefix to access them later in Sieve scripts, for example sieve_env_hello = hello changed to "${env.vnd.dovecot.config.hello}". But now I am getting an error

doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf line 11: sieve_env_hello: Unknown setting: sieve_env_hello

Thank you in advance!