The border of button appears automatically. How to close it so that it will never appear? Thanks. The button in sweetalert2
I guess you are talking about the outline of a focused button:
It's possible to remove that outline from buttons, but PLEASE DO NOT DO THAT.
There's a reason for that ugly outline!
You're killing the keyboard accessibility of your app. People with vision disabilities, as well as keyboard-ninjas, will hate you for that.
SweetAlert2 authors were working hard to make that plugin accessible to all users, by removing buttons outline you simply ruin their effort.