How to add a logpoint?

[Rizhiy]

It says that logpoints are supported, but I can't seem to get them to work.
I'm trying to set them as follows:

dap.set_breakpoint(nil, nil, vim.fn.input("Log point message: "))

but nothing seems to get printed.

I'm using nvim-dap-python to run method tests.

[Rizhiy]

I've enabled nvim-dap-ui and now what I want gets printed, but only on the first pass. If the code goes over the same place again, it doesn't print the updated value.