CocoaMQTT
MQTT 5.0 client library for iOS and macOS written in Swift
...On your application targets “General” settings tab, in the "Frameworks, Libraries, and Embedded content" section, drag and drop CocoaMQTT.xcframework, CocoaAsyncSocket.xcframework and Starscream.xcframework from the Carthage/Build folder on disk. Then select "Embed & Sign".