このテーマの使い方は？

[m10n]

I am trying to get this theme/skin on my discourse but can’t find it https://community.revolut.com/

Can anyone please help me?

TIA.

[RGJ (Richard - Communiteq)]

It’s a custom theme, based on this theme GitHub - Eagle19243/Discourse_New_Theme
Note that the license of that theme is unknown, so you should check if you can use it.

[merefield (Robert)]

You could in any case create your own similar one by learning a bit of CSS, learning the relevant Discourse settings and using the browser inspector to examine the CSS as it will be fully exposed.