Opening a 75% window in Facebook messenger

I want to add a link in payload button in that way that it will open a 75% window in facebook messenger. How can I achieve that? Thanks in advence.

you need to add link in the button instead of payload that way it will open like the way you said.

But it will open a full window instead of 75%. Is there any way to get that? I show it work on manychat, chatfuel .