When I got my phone not trusted on setting certificate. What I have to do it?

Hello kimleng54,

Thanks for posting in Apple Support Communities!

We understand that you that you're seeing a Certification that is not trusted on your device. We'd like to help.

We see that you're coming to us from Lists of available trusted root certificates in iOS.

Did you install a certificate profile on your device? Tap "More Details" to get more information about this certificate. Here's some information about how to Trust manually installed certificate profiles in iOS and iPadOS.

Take care.

 kimleng54,

If you're unable to trust this certificate, we would suggest contacting Apple Support directly. Here's how to Get Support.

Have a nice day.