Step 3. Modify your website theme
In order for you to use DX8 on your existing website, you need to add our cohesion-placeholder tag to your custom theme.
DX8 uses render placeholders of inline CSS and as these cannot be naturally injected into the HTML template, the site's theme needs to contain <cohesion-placeholder></cohesion-placeholder> within the <head> tag.
To enable DX8 on a custom theme you must add
cohesion: true to your themes .info.yml file.
After following the above steps and your theme is installed, a Cohesion rebuild is needed to create the required templates.