Lightning Network – How to force a channel to close in its original state for a good reason

A few months ago I created a payment channel from LND’s desktop node to Blixt’s mobile node. I then tested a few payments between nodes and the final balance on my phone is now around 20K sats (not that much). Unfortunately, my phone crashed and I am currently unable to cooperatively terminate the payment channel. Also, since I only used the Blixt wallet for testing purposes, there is no backup. The only option you have to retrieve funds from a mobile node is to force the channel to close using its original state when the Blixt node balance is zero. I know for sure that the mobile node cannot react and broadcast the penalty transaction because it crashes, allowing me to “steal” 20K sats from my mobile wallet. Unfortunately, I have no idea how to do this technically.

Can someone help me?