Enable Redis PHP Extension from Plesk
Reference KB:
https://bobcares.com/blog/install-redis-on-plesk/
https://supporthost.in/install-redis-on-a-plesk-server/
Step 1: Enable EPEL Repository
Step 2: Install Redis
Step 3: Start the Redis Service
Step 4: Check Redis Service on Port on 6379
Step 1: Check the PHP Version and the PHP Handler the hosted website is using
Step 2: Click on Tools & Settings >> PHP Settings
Step 3: Click on the appropriate PHP Handler
Step 4: Enable the Redis Extension