A lockscreen requires you to enter a PIN or password to access your mobile device and helps protect sensitive information from prying eyes.
Beginning July 15, 2019, SHC requires the use of a lockscreen to access G Suite applications on mobile devices.
Follow the appropriate instructions for your device below:
For Android:
https://support.google.com/android/answer/9079129?hl=en
For iOS:
https://support.apple.com/en-us/HT204060