How do I install VirtualBox Guest Additions when running Silverblue as a guest?

I get read only filesystem, which is completely expected, but I don’t know how I would go about installing VirtualBox Guest Additions.

The read only filesystem is when trying to install via the inserted ISO image. When trying to install with rpm-ostree, it looks like it is already installed, but it definitely doesn’t seem to be working with things like dynamically updating the resolution on window resize.

$ sudo rpm-ostree install virtualbox-guest-additions
error: "virtualbox-guest-additions" is already provided by: virtualbox-guest-additions-6.0.4-2.fc30.x86_64. Use --allow-inactive to explicitly require it.