Board Thread:Support Requests - Getting Technical/@comment-4530178-20180407161739/@comment-27345308-20180409045148

InfoboxBuilder has been around since March 2016 and they added the Source Editor button a few days after, so not exactly a new feature.

Do you not see the  button in the bottom right corner? This is what it's supposed to look like.

Edit: wrote top right instead of bottom right corner originally, whoops.