Getting issue in keychain: iPhone Distribution Certificate is not trusted

I'm working on iOS enterprise application, now our iOS distribution certificate is expired and I'm creating new certificate using below steps:

1. Create certificate sigining request from keychain access.
2. Login with developer.apple.com and generate distribution certificate using certificate sigining request.
3. download new iOS distribution certificate and install.

After this I'm able to see iOS Distribution certificate in keychain access but getting error: "iPhone Distribution certificate is not trusted".

Also, I have tried it using Automatically manage signing, and tried to export ipa file, but I'm getting below error:

Please help me to resolve this errors.

Just download the certificate from here and install it. If that doesn't works have a look on https://developer.apple.com/de/support/expiration/.

https://developer.apple.com/de/support/expiration/ should be the answer. Just install the certificate manually or upgrade to Xcode 11.4.1 or later. After upgrading to Xcode >= 11.4.1 I had to open a Xcode project and had to wait few seconds. Afterwards the new Apple Worldwide Developer Relations Intermediate Certificate automatically has been installed.