How to add participants in between the group call?

Step 1 :

Click on the + button to add more members to the ongoing call, as directed by the arrow from the figure below.

An Add Users window opens.

Step 2 :

Search or scroll the sidebar to add members as directed by the arrows here in the image below.

Find all the members of the group when scrolled down.

Step 3 :

Find the selected members here.

Step 4 :

Click add participants.

The newly added participant will join the call.

End

Notes

The blue colored arrows used in the figures are not part of Troop Messenger's user interface. Used them for representational purpose.