How to check if the exec() function is enabled in my PHP install

I am NOT a technical person, so im trying to download a backup manager extension for my app on the droplet but it requires:

the exec() function enabled in your PHP install since it will call a few command line commands to create the backups. Additionally, this only works on a linux environment where the “tar” and “mysqldump” commands are available (99% of linux servers have them)

is there detailed steps on how i can do this in putty or winscp? i have a lamp on ubunutu 20.04 using php version 7.4.3