iOS 14 and iPadOS 14 added the convenient ability to tag individual people in group messages in the Messages app. Here’s how:
° With a Messages conversation open, touch and hold a message bubble, then tap the Reply button.
° Type your message, then tap the Send button.
You can reply to a specific message in conversations with one person and in groups. You can also use “mentions” to call attention to certain messages and people. Here’s how:
° With a Messages conversation open, type a contact’s name, then tap the name when it appears. Or type @ followed by their name.
Depending on your contact’s settings, a mention can notify them even if they’ve muted the conversation. To change this notification setting, go to Settings > Messages, then turn Notify Me on or off.
(This how-to is based on my experiences and info on Apple’s support pages — where the images sometimes come from.)