Kimmo

You will want to manually upgrade
Check your server meets the current requirements using the requirement checker. You will need to update to php 8.1 at least -
  Upload a fresh set of files from your client area, overwriting any files which already exist. 
  Run the upgrader from /admin/upgrade and follow the process through Of course this is done after making a full backup of both files and database.

You upload the new files to the server in the same location as the old ones and then run the upgrade script from /admin/upgrade/ in your browser.
In case the site is big, the upgrade script might ask you to run some manual MySQL queries from SSH.
 
For more info look at the Manual Upgrade section of this guide:
 
However, check first if your server has all the requirements to run the latest version:
 
Quick note: the check script will give you the green light also for PHP 8.2+, but only PHP 8.0 and 8.1 are supported. 😋
 
If you're unsure of how to proceed yourself or just want someone to help, it's possible to hire a 3rd party provider to do the upgrade for you: https://invisioncommunity.com/third-party/providers-directory/
I'm also on that list if you want to send me a PM.
 
EDIT: @Marc Stridgen beat me to it. 😛

Very nice looking and nice features. 
 
Please keep in mind that many of us use advertisements as our main source of funding to keep our sites going. I don’t see much room for ads in any v5 snippets.