Where are the subtitles (personalized signature or user name) on Xiaomi 1S when it locks the screen?
You first find the system tools, click "Settings", then find "Security and Privacy", click in and you will find "Screen Security Protection", then click in and select "Owner Information", and enter the information you want to enter, such as your name. If you choose "screen password", it means that you have set your own password. There are three types, but don't forget when setting them.