What's the problem?
Sometimes you may notice that although you have First Name/Full Name/another name variable in the opt-in message connected to any widget that has "with the checkbox" button type in it (for example Button, Box, Modal, etc.), the message is being delivered to your contacts without their name in it.
How you see the message in your flow
How it sends to your contacts
The reason why this happens is that due to Facebook limitations, ManyChat variables only work in opt-in messages connected to the widgets with the "Send to Messenger" button type.
How to troubleshoot
To solve this issue, you may either edit your opt-in message so that it looks nice without the user name, or change the type of the widget button to "Send to Messenger".