To set the smart lock on body is may the most comfortable, but it is also not the most secure option. The device notices by sensor when it is carried and unlocks instantly. As it can not recognize by whom it is carried, everyone can simply unlock it.

Android 9
Step 1:  Open the  settings
Step 2:  Tap on  Security & location
Step 3:  Tap on  Smart lock
Step 4:  Tap on  On-body detection
Step 5:  Activate or deactivate  On-body detection
Step 6:  Confirm with  CONTINUE
  1. Open the settings
  2. Tap on Security & location
  3. Tap on Smart lock
  4. Tap on On-body detection
  5. Activate or deactivate On-body detection
  6. Confirm with CONTINUE

Android Instructions
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