strange problem
This title appears in a Google search
https://localhost/im-create-thread/78
1 - When anyone clicks on it, you can send a message to the advertiser without logging in
it's a problem
2 - It is also assumed that this page does not appear in Google search
Thank you all

There is no option to tell osclass from plugin side if particular page should or should not be indexed.
You can require login for instant messenger plugin (i.e. https://plugins3.abprofitrade.eu/im-create-thread/1168)

https://plugins3.abprofitrade.eu/oc-admin/index.php?page=plugins&action=renderplugin&file=instant_messenger/admin/configure.php
"Login Required"