To connect your Google Analytics data to Funnel, select Data sources in the left-hand navigation bar:
Hit '+ Data Sources' to open up the data sources popup and click the Google Analytics button in the top right:
After that, the connection of Google Analytics is done in 3 steps:
Select what Google-User to authenticate with.
Give Funnel permission to access your data.
Select what Google Analytics views to connect.
Each Google Analytics View you add will be listed on the Google Analytics page. You can see their respective status, remove them, as well as reconnect them if necessary.