Simultaneous shared parking

[CWR]

That is what you need - a standard capture of the calls from the 3cx server. Start Wireshark. Wait 10 seconds. Start the process.
Complete the process. End the call. Wait 10 seconds. End Wireshark.
I just always add 10 seconds to both sides to make sure it captures everything.
Post it to a Dropbox or Onedrive account as sometimes the files are too big to post here, and share the link.