Yamiraan
Yes, its a free plus, I think You can install it automatically in aaPanel only click on add Redis extension. When no, he warn You to before install in App manager.
Dont forget set password too and limit memory for Redis (example of 8GB ram is 2,5GB). Redis can eat 6GB and more without problem.
In Wordpress plugin Litespeed cache set a database key for each site (start from 0, 1, 2... to 16 in default).
I try before free Redis WP plugin but without paying for premium is terrible(not max speed) . Litespeed plugin make all work perfectly at maximum.