Copy two columns from the Google Sheet, users and key. Then replace all the '\t' with '='. Name it as credentials.txt. Run this script. It should create the users for you.

create_users.sh

#!/bin/bash

while IFS='=' read USER KEY
do
    if [ ! -d "/home/$USER" ]; then
        sudo useradd -m $USER -g snal
        echo created user $USER
        sudo su - $USER -c "mkdir /home/$USER/.ssh; echo $KEY > /home/$USER/.ssh/authorized_keys; chmod 600 /home/$USER/.ssh/authorized_keys"
    else
        echo $USER already created
    fi
done < credentials.txt

Let me give it a try!

Thanks for sharing it ;)