How to remove someone from Chat in Messages

That does not look like any part of Apple Messages I’m familiar with, and the closest match I can find seems to be Facebook Messenger. (Which I have no experience with.) If I’m correct and this is Facebook Messenger, you will want to ask Facebook Support.

This is the Apple Messages app icon:

This is what the Apple Messages group chat display looks like:

With the Apple Messages group chat, here is how to add and remove people > Add and remove people in group text messages on your iPhone, iPad, or iPod touch - Apple Support

But if this is some other chat app such as Facebook Messenger as I’d suspect, ask the support team for that particular app.

No attachment.

I’m unclear how “PickleballMaster” fits in here, and cannot see what you are seeing, and do not know about what is installed and in use on your iPhone. Put differently, you’ll want to provide a screenshot or other details about what you’re encountering here.

This is with the Apple Messages app, and not another chat app?

Can you post a screen shot, with any personal data masked?

For how to do that, see > Take a screenshot on your iPhone - Apple Support