oh, we can't change that default SSID of plug Wi-Fi.
BTY, why do you want to change that SSID?

If for example we use this socket to program lamps, or other devices at home to simulate presence, anyone who sees WiFi networks from the outside will know that there is a socket and that it is possible that no one is at home. It would be better to be able to rename the SSID ... or hide it when the device has been configured.

When you connect the device to your home wifi it should no longer be broadcasting it's AP SSID.

Bit of a stretch though - I believe most burglaries are smash and grab rather than sophisticated stakeouts with watches, diaries, and wifi scanners. They're probably looking for a dark house when they drop by, not waiting all evening to see if/when the lights turn on... if they even break in at night, many break ins are during the day when the occupants are at work/school.