Notification that the second line is busy

Hi guys!
I have FreePBX 15.0.17.34 with Asterisk 18.3.0.
I use ‘Follow me’ option.
When the second subscriber calls, he hears MoH, but doesn’t know that the first line is busy.
How can I notify the subscriber that the second line is busy?

You can set up a system recording (under Admin).
Then under the extension in follow me, you can set the announcement to the recording to you set up earlier.
The recording can be that the line is busy.

This does not fit.
Follow me Announcement plays always, even when the line is free.
Options description: “Message to be played to the caller before dialing this group”.
I need the Announcement to play only when the line is busy.