Not sure if Operation and ProcessTeams are aware of this.
If no, I would suggest an urgent meeting with them to settle the process first - who to do this (sales)?, when to do this (after payment)?, How to do this?
On parallel, we need to identify where to put this message in shop and it should be in line with where this activity happens ka.
After we can identify where we put the message, we then can make decision if it's the sticker or something else.