Elastic Beanstalk ignore HTTP 404 monitoring option not available

I want to prevent my Elastic Beanstalk application from triggering degraded health when there are 404 responses.

This has been answered on StackOverflow and I can see the setting indeed:

However, once I click the "Edit" button, this setting is nowhere to be found:

If I switch over to the "new Elastic Beanstalk console", that setting is missing there as well.

How do I turn off health degradation on 404 responses?