How to send pm?

Hi,
Many abject apologies, but I cannot find the answer as to how to do a Purple Moosage. I wanted to contact someone about the Florida betony he has & went to his page but saw no way to do a PM. Is it because I don't have enough rewards?

Thanks!

If they have PMs enabled, you can go to the profile page by clicking their name and near the top right is an envelope (next to the pie).  From there, you can write your message and send.

Although it may look a bit different in mobile view, the steps are still the same.

Thanks so much.