Did you try installing it - is the tool available in Galaxy's analysis interface, under the section you selected when installing it?
If it's installed, you should be able to find the tool by becoming and Admin user (see https://wiki.galaxyproject.org/CloudMan/Services/Galaxy#Becoming_a_Galaxy_Admin_user) and then browsing Galaxy's Admin interface, under 'Manage installed tools'.
The repository is in the Galaxy Main ToolShed here: https://toolshed.g2.bx.psu.edu/view/lparsons/htseq_count/a6dcb86af112
It can be added to any cloudman instance through the Admin functions.
Hopefully this helps, Jen, Galaxy team