Wheel

Raspberry Pi OS does not have the wheel group by default. It can be added with

sudo groupadd wheel

A user can then be added to the wheel group with

sudo usermod -aG wheel username

The -a flag appends the group, such that the user is not removed from all groups that are not explicitly listed in this command. The -G flag specifies the groups that the user will be added to, listed directly after the flag.

Whether the user is now added to the group can be checked with

cat /etc/group

There should be an entry similar to

wheel:x:1001:username

This entry confirms that the user has been added to the wheel group.