Moodle

Hello, the h5p plugin is disabled in default. And it doesn't show up on manage activities. I would like to know how do I enable it in such case?
Moodle version is 3.8.2
What I tried (but not working)
1. Select another theme
2. Clean cache
3. reinstall plugin
Thanks.

\ ce command not recognized within the H5P I installed on moodle:

Hello, I'm not able to write mathematical expressions and chemical formulas inside the H5P that I installed in Moodle 3.8. Before installing the H5P plugin I used to successfully write formulas and chemical reactions in Moodle. For example, the command

  \(\ce{Bi}\)    +     \(\ce{HNO3}\)      \(\ce{->}\)       \(\ce{Bi(NO3)3}\) +  \(\ce{NO2}\) +  \(\ce{H2O}\)

Hi!!!

I recently got acquainted with the features of h5p and it is very cool! I use Moodle 3.7.1+ (Build: 20190801) and H5P 1.20.2, MathDisplay (1.0.5) is installed. But there is a problem: I need to use mathematical symbols in my work. Always used mathJax. I can't do anything to display mathematical symbols. There are JS errors in the Chrome console. What am I doing wrong? I have already studied all the options...(including those in the documentation). Does not work... It is also noted that installing on a second-level domain does not cause problems.

Save me!