Adding a fixed, centered encrypted message at the top of every channel using the - SwiftUI SDK

We are working on customising our design and have encountered a new requirement.

We need to display an encrypted message at the top of every channel. This message should remain fixed at the top of the channel, similar to a regular message, but with a custom, centered design (see attached image).

I tried pinning the message, but it still appears as a regular message without the expected fixed behavior (see attached image).
I am aware of the isPinnedMessage property, which should be set to true, but I am unsure where and how to set this property.

Below is the code I used to pin the message:

channel.pinMessage(messageId: message.messageId)

What we achieved using pinMessage:
It follows the standard message format, which is not centered, does not occupy the entire screen height, and includes the tick icon.

What we want to achieve: