The invitation is your business card to introduce yourself to a user. In the invitation section, you can view all the invitations you have sent and their status.
The status can vary:
"You invited Miriam to chat": In this case, the invitation is pending acceptance;
"Send a gift": In this case, you have the option to draw the user's attention with a gift;
"Available in...": In this case, the user has set a daily invitation receiving limit, but you can contact them the next day when the status updates to "Available again."