FCALL_RO
Syntax
        FCALL_RO function numkeys [key [key ...]] [arg [arg ...]]
- Available since:
 - 7.0.0
 - Time complexity:
 - Depends on the function that is executed.
 - ACL categories:
 - 
              
                
@slow,@scripting, 
This is a read-only variant of the FCALL command that cannot execute commands that modify data.
For more information about when to use this command vs FCALL, please refer to Read-only scripts.
For more information please refer to Introduction to Redis Functions.