For anyone still struggling with this, here are the steps you need to take:
- Go to your analytics dashboard at analytics.google.com
- Click on the bottom left Admin button
- From there click Create property
- Enter a name for your property (ex. Shopify)
- On the bottom, click Show advanced options
- Check Create a Universal Analytics property
- Enter your website
- You can select the option to create both or just the Universal Analytics (this is the one Shopify needs)
- Hit Next and copy the property the ID that starts with UA-
To give a bit more context, Google recently made an update to create by default a Measurement ID (that starts with G-)instead of a Tracking ID (that starts with UA-). Shopify only accepts the tracking ID at the moment.
Hope this helps anyone else!