Removing Agent Joined and Left Message Prompt/SYS Message in Facebook Chat Session

we have integrated Facebook with BPCC Agent desktop. so once an agents connects with the chatter(Fb user), there is a prompt/system message which says
"ztest 01 agent 01 " has joined the session, is there a way that this could be removed and chatter(Facebook Customer) does not see this.

These messages can be edited at Admin Portal → Scenario Entries → Massaging/Chat → Chat Widget → Chat Styling.

Unfortunately currently we can not completly remove the messages as if you leave it empty the default phrase will be used, it’s hardcoded.
Perhaps, you could switch to another phrase like “Session started” or if you would like to remove it completly we could treat this as a PER.

We did try to rename this but this is not happening for facebook integration.
it works only if it’s a native chat.