Removing the bot icon for a few bot uttered messages to make it look like a system uttered message outside of the conversation

[Wing-e7]

I want the chat bot to out put a message in the middle of the conversation. This would say something like " 10 days have passed since". This doesn’t seem to be a problem but,

I want this message not to have the bot icon beside it and would want it to be centered in the chat screen.

Is there any way to achieve this ?