Good evening everyone. Could someone please explain to me how to send a private message to a user?

From a mobile phone, click

1. The arrow on the top right 
2. The notification Symbol (white on white background, what a great design choice...)
3. "New Message 

Then you can search for a user. 

Thank you, you've been very kind.
I would have never found this notification symbol on a white background.
I should be okay now 

That works. If you don't have access to a desktop computer, a workaround is to go to the 3-dot menu and check "Desktop site," but that makes other aspects of the forum difficult to use.

FWIW, I've mentioned this in the moderators group.

The simplest way is hovering over the user name, and then selecting "Send Private Message" from the context menu that pops up. It works both on a computer with a mouse, as well as on a phone (long-tap instead of hovering with the mouse).

iPhone

Same here on my older Android phone. The options are:

• Guess where the icons are located
• Change settings to "Desktop Site"
• Use a desktop computer. I'm assuming this is not the OP's preferred method.