Adjusting inventory should be done by editing the event in Event Ticketing. While you can edit inventory directly from Shopify, it’s not currently possible to sync those inventory changes back to Event Ticketing - this means, that if you later went and edited the event in Event Ticketing, your previous inventory edits in Shopify would be overwritten with what is set in Event Ticketing.
Adjusting Capacity must be done from the Event Ticketing app.
You may edit inventory manually in Shopify in a pinch, but it should be a last resort.
From the events list, click on an event to bring up the stats page.
If you need to make any changes including inventory, prices, event details, etc, click on Edit, which will bring up the familiar event set up form.
There are two ways inventory is managed: normal (each variant has it’s own inventory level), and Capacity. Learn more about the event capacity feature here.