Error notice in list tags page - List all tags page with no results

Hello,

I have just installed vm2tags and succesfully added some tags and the tag cloud module. I have 1 issue I need help with:

1. When I click on a tag and then view the Products tagged as ".." page
(here is the link xartomanteio.gr/index.php/component/vm2t...%84%CE%B1?Itemid=786 )
I see this Notice: Undefined index: Itemid in /home/.../public_html/components/com_vm2tags/router.php on line 29.
I checked with the default joomla template too and the notice remains.

I would also like to ask if there is a documentation page/file.

Thank you!

Here is my installation info:
PHP Version 5.6.30
Web Server Apache
WebServer to PHP Interface litespeed
Joomla! Version Joomla! 3.6.4 Stable [ Noether ] 21-October-2016 16:33 GMT
Joomla! Platform Version Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
VirtueMart 3.0.18

Please ingore the second part of my ticket subject " List all tags page with no results "
Thanks again

& the notice is gone! Hope it doesn't appear again
I didnt do sth about it, I just added some extra tags but can't see how this would be relevant...
I am attaching a screenshot of the page when the notice was still there in case it is helpful to you.

Hello

Sorry the screenshot is too small.
Let me know if anything doesn't run as expected.

ok! I am attaching it again

I would also like to know if there is documentation for the component.
& I see a new issue: the prices shown are without tax although I have checked the 'yes, with tax' option.
Thank you