How to add a second person to the QB account so that "second person" can access the QB account in my absence.

Thanks for reaching out to the Community, hl.hackney. I can definitely see how adding a second person to your account would be helpful. I'll guide you through how it's done.
 

You can invite users from within your settings.
 

Here's how:
1. Go to your Gear (⚙) icon, then Manage Users. If you're unable to use this option, you'll need to contact an admin user for assistance with managing other profiles.
2. Click Add user.
3. Pick their user type.
4. More options will appear on your screen depending on the one you chose. Input any requested info.
5. Enter the new user's name and email address.
6. Select Save.
 

Once you've sent your invitation, the new user will receive an email from Intuit. It will display your business's name and a message reading "Ready to get started? Let's go!". After using their Let's go! link, an account creation or sign in page will be presented. They'll need to enter the requested info to create a new account or sign in, depending on what they see.
 

You can find more details about different types of users and what kinds are available with your specific QuickBooks Online subscription in our following article: User types & user permissions

If there's any additional questions, I'm just a post away. Have a wonderful Friday!