I'm trying to create a calculated field for a Jira project. I'm running Jira Cloud. I'm trying to follow the Adaptavist docs at https://scriptrunner.adaptavist.com/5.0.4/jira/scripted-fields.html
In the "Getting Started" section, the docs say to add a new custom field, choose Advanced and then Scripted Field:

There is no 'Scripted Field' option in my install:

I have ScriptRunner for Jira installed:

Is there some way to enable Scripted Field that I'm missing?