[Plugin: Optimized LaTeX] folfer cache make the maths formulae not appear

hai tq for the nice plug in…i just follow the following instruction

1. Upload the plugin source to the /wp-content/plugins/ directory

2. Activate the plugin through the ‘Plugins’ menu in WordPress

3. Make sure the folder /wp-content/cache/ exists and is writable.

after finish step 2, i can see my equation but after i create the step 3 i.e cache folder in side /wp-content/cache and when i view all the equation not appear in my post Hello world!…

any guide for it..currently the plug in is active without any equation which i write appear

Q2:

how to make sure cache folder is writable??

nik
https://mathslabfx.com/

https://www.ads-software.com/extend/plugins/optimized-latex/