When you need help with custom clients, please post in the thread you got it from in the future, in this case:
viewtopic.php?f=49&t=40400 Support for custom clients should be taken up by those that made them and the community that uses it. Thanks.
The default to toggle the UI display is the space bar. Sometimes you have to toggle the UI display a few times for it to show up properly. There is some saved information you can get to, but I don't recall off the top of my head where it can be accessed at.
I don't use Amber myself, but don't see anything explicitly listed as changing this default keystroke. Might be something in the options.
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