Best PHP handler for LSWS

Hi all i am new to LSWS and i am configuring some settings.
I have a problem that wordpress wp-admin is very slow with LS cache plugin so after some research some suggested that i have slow php.
When i turn of the LS Cache wp admin is very fast. So i had enabled suphp handler and i changed it to fcgi in WHM miltyPHP manager but still wordpress dashboard is slow.
Do i need to configure LSAPI in LSWS configuration - External Apps? Is that the best solution for php handler with LSWS?
Will it fix my wordpress problem?

I forgot to mention tha i am using php 7.4