Use lldb command line when debugging with dap-mode

I (sometimes) use dap-mode to do C++ debugging on MacOS with lldb as the debugger. How do I issue commands to lldb directly using the command line? The dap-ui-repl doesn't do this, here I can execute code directly when a breakpoint is hit, but I do not seem to be able to reach lldb itself. Is there a way to do this in dap-mode?

Refer to the debug adapter docs, but I think that some of them can do that in `dap-ui-repl` by prefixing the command (believe `'` was the right prefix).