You can enable dark features using either of these methods.

Through system properties

This option is more suitable for someone that manages a large number of instances, as it is a method that can be automated to set these features on startup. First, read the Setting properties and options on startup tutorial for your operative system in the Atlassian documentation site.

The property key that you are enabling must be preceded by "Datlassian.darkfeature".

So, if you want to disable the onboarding experience, which is an Atlassian dark feature, you should locate the property key which in this example would be: "jira.onboarding.feature.disabled". When setting this property through system properties, your key should look like this:

-Datlassian.darkfeature.jira.onboarding.feature.disabled=true

Through the browser

This is an easier way to turn a dark feature on, suitable for admins that manage a single instance. Log in as a user with administrative privileges and paste the following at the end of your site url:

/secure/admin/SiteDarkFeatures!default.jspa

From here, simply paste the property key into the text box labelled "Enable dark feature" and click Add.

Example:

enable dark feature

For how-to questions please ask on Atlassian Answers where there is a very active community. Adaptavist staff are also likely to respond there.

Ask a question about ScriptRunner for JIRA, for for Bitbucket Server, or for Confluence.