User isn't in the sudoers solution

Use sudo to prompt "xxx is isn't in" Sudoers file. This incident would be reported. where xxx is your username, that is, your username does not have permission to use sudo, we just need to modify the/etc/sudoers file. Here's how to modify it:

1 into Super User mode. That is, the input "Su-", the system will let you enter the superuser password, enter the password after entering the Super User mode. (Of course, you can also use root directly)
2 Write permission to add files. That is, the input command "chmod u+w/etc/sudoers".

Note: The/etc/sudoers file is a read-only file
3) Edit the/etc/sudoers file. That is, enter the command "Vim/etc/sudoers", enter "I" into edit mode, find this line: "Root all= (All)" Add "xxx all= (All) all" (Here xxx is your username), and then save (the first one The ESC key and enter ": Wq" to exit.
4 Revoke file Write permission. That is, the input command "chmod u-w/etc/sudoers".