If you’re up for experimenting, you can still follow parts of this Umbrel guide…
The fact that your Umbrel is “crashed” doesn’t mean you can’t gain access to the LND directory to access the content of that LND directory with another Linux computer. Once you have those LND contents, you can still follow the bulk of this guide, which itself has a step that involves pulling the Umbrel contents into a local directory.
If the only thing you have access to is your seed phrase (bad… because you won’t have access to any of your channel funds or be able to force close them) then your best bet is restoring outside of LND on StartOS, with either an advanced wallet or with LND installed on another a less opinionated OS.