Two things ... "softaculous' and 'shared hosting' ...
Maybe the reason one cannot find much on 'shared hosting' is because it's not good environment for Moodle.
May not be able to install nor configure software for document conversions needed for grading ... ghostscript, unoconv (python), and certainly not the 'listener' service as those would be server wide ... all customers on the shared host.
Think, with shared host, you will have to try using Google for document conversions ... and if that doesn't work ...
seek better hosting.
Reading your comment make me stop finding solution that never exist.
How about if I move to Virtual Private Server? will I be able to solve the problem? Can I still use softaculous in VPS?
Oh yeah! Forgot to 'comment' on Softac ...
IF you move to VPS ... stand a better chance of solving issues and getting support suggestions ... just don't go for cheapo VPS with little space.
Yeah ... Softac will install OK, although no documentation on how it installs other than what users discover about ... usually after a failed update/upgrade to Moodle. That's when providers will bail on ya and tell you to come to these forums to resolve the issue ... hmmmm created by commercial software that provider provided you, the customer, with no support.
Bottom line ... *criminal*
Have never seen a Softac person in these forums!
Thank you for your advice, sorry if my word selections sometimes are not appropriate, I use english as a second language. For now, I am thinking about moving to VPS then.