Documentation:

Notes on Wordpress (App wordpress)

How to install plugins and themes

When you run Wordpress, you usually install Wordpress plugins and themes by logging into your Wordpress installation as administrator, navigating to the plugins and themes pages, and pick install new ones from there.

This is not how it works on UBOS.

When you run Wordpress on UBOS, you need to specify your Accessories at the time you create your Site, or by redeploying the Site later with an updated configuration.

Example: let’s say you want to use the Wordpress “Pinboard” theme for your Site. When you create the Site with ubos-admin createsite, you specify wordpress as your App, and wordpress-theme-pinboard as an Accessory. You can specify multiple Accessories.

Here’s the reason why: UBOS cannot manage Apps that change their code base without UBOS knowing, and that’s what would be happening if Wordpress got to add themes or plugins to itself. And: UBOS curates plugins and themes, so you can be fairly certain that the ones provided through UBOS actually work.