neovim dapui configurations

I have copied the neovim-dapui config from the git repository to my dap.lua file:

require "dapui".setup({
  icons = { expanded = "▾", collapsed = "▸", current_frame = "▸" },
  mappings = {
    -- Use a table to apply multiple mappings
    expand = { "<CR>", "<2-LeftMouse>" },
    open = "o",
    remove = "d",
    edit = "e",
    repl = "r",
    toggle = "t",
  },
  -- Expand lines larger than the window
  -- Requires >= 0.7
  expand_lines = vim.fn.has("nvim-0.7"),
  -- Layouts define sections of the screen to place windows.
  -- The position can be "left", "right", "top" or "bottom".
  -- The size specifies the height/width depending on position. It can be an Int
  -- or a Float. Integer specifies height/width directly (i.e. 20 lines/columns) while
  -- Float value specifies percentage (i.e. 0.3 - 30% of available lines/columns)
  -- Elements are the elements shown in the layout (in order).
  -- Layouts are opened in order so that earlier layouts take priority in window sizing.
  layouts = {
    {
      elements = {
      -- Elements can be strings or table with id and size keys.
        { id = "scopes", size = 0.25 },
        "breakpoints",
        "stacks",
        "watches",
      },
      size = 40, -- 40 columns
      position = "left",
    },
    {
      elements = {
        "repl",
        "console",
      },
      size = 0.25, -- 25% of total lines
      position = "bottom",
    },
  },
  floating = {
    max_height = nil, -- These can be integers or a float between 0 and 1.
    max_width = nil, -- Floats will be treated as percentage of your screen.
    border = "single", -- Border style. Can be "single", "double" or "rounded"
    mappings = {
      close = { "q", "<Esc>" },
    },
  },
  windows = { indent = 1 },
  render = {
    max_type_length = nil, -- Can be integer or nil.
    max_value_lines = 100, -- Can be integer or nil.
  }
})

There are two problems:

1. changing the dapui layout

None of the changes I make in setup (removing some elements, changing the position from left to right, etc), has any effect in the layout.

If I remove the above setup and use the setup below, I can make changes in the positions:

-- dapui.setup {
--   sidebar = {
--     elements = {
--       {
--         id = "scopes",
--         size = 0.25, -- Can be float or integer > 1
--       },
--       { id = "breakpoints", size = 0.25 },
--     },
--     size = 40,
--     position = "left", -- Can be "left", "right", "top", "bottom"
--   },
--   tray = {
--     elements = {},
--   },
-- }

I'm not familiar with lua and I couldn't find any help in dapui documentations. What is the difference between layout and sidebar and tray?

2. Adding embedded MCU peripherals to the layout

I downloaded the svd file for my MCU and added the path to it in dap.configurations.c. But I don't know what element should I add to dapui setup to display peripherals in the layout.