Xiaomi
Set Up Screen Lock with Pattern, PIN or Password auf Xiaomi
MIUI ships without a mandatory unlock method, so many Xiaomi phones stay protected only by a swipe gesture. That leaves the device open to accidental touches in a bag or pocket, and to anyone who simply picks it up.
The screen lock function sits inside the security settings and lets you choose between a Pattern, PIN or Password as the unlock method. Once set, this code also becomes the fallback whenever fingerprint or face unlock fails to recognize you, so it needs to be something you can reliably remember.
To activate it, go to Settings ➔ Passwords & security ➔ Screen lock, then choose Pattern, PIN or Password and confirm with Got it. Enter your chosen Pattern, PIN or Password, tap Continue, then enter it again and tap OK to save it.
A Pattern is quick to draw but easier to spot over your shoulder, a PIN balances speed and security, and a Password offers the strongest protection at the cost of typing speed. If you mainly want convenience rather than maximum security, biometric unlock combined with any of these three as backup is usually the better setup.