My cash and positions got transferred to Apex Clearing when the broker I was using shut down. How do I move to a new broker?

I can't do anything with my cash or assets there. It's all just sitting there. I can't buy, sell, or transfer out.

I need to move to a new broker but their website offers zero information. I've been googling and looking around for days but have found no solutions.

I've been trying to get help but my posts get removed. I am completely in the dark here.