Dialing to add number to block list

[mk1518]

I read the documentation here about the commands to add a number to blacklist:

https://freeswitch.org/confluence/display/FREESWITCH/mod_blacklist

I followed the example, here's my dialplan:

<extension name="add_to_block_list" continue="false" uuid="xxxxxx">
    <condition field="destination_number" expression="^\*9567(\d+)$">
        <action application="answer" data=""/>
        <action application="set" data="fake=${blacklist(add bl $1)}"/>
        <action application="playback" data="/var/lib/freeswitch/recordings/mydomain/number_blocked_8khz.wav"/>
        <action application="event" data="${blacklist(save bl)}"/>
    </condition>
</extension>

Here the blacklist "bl" is the name I created under FusionPBX's "Call Block" module.

After dialing in, however, I heard the confirmation file play but cannot find this number on the black list under "Call Block".

Did I misunderstand this module?