How to private message in Roblox?

Some players in Roblox say “pm me if you have a suggestions” or something like that. I was wondering if anybody could tell me how to private message in Roblox?

from the Roblox Support page "How to Send Messages to Other Players"

If you are not already friends with the person that you would like to communicate with, you can still send them messages as long as you and they have allowed this in their privacy settings. To find them, type their username into the search bar at the top of the screen and choose the Search (username) in People option in the set of choices that will pop up. Click on their name in the list of search results and it will take you to their profile where you can click their Message button.

It's very easy. There are two options, depending on whether the user you'd like to contact has safechat or not.

Safe chat version: If the user has safechat, then you have to search their username, then click on the person you wish to contact. On the right of their user picture, there is a button which you click and it should friend the person. Then, once they accept, you can click Message, which should be a button in the same spot, and you can message them!

Non-safe chat version: This one is very easy. You search up their username, then click the person you wish to contact. Beside their user picture, on the right, click the three dots and click Follow. Then you will be able to click the Message button and message them.