Change ltex-ls settings

Hi all,

I am trying to change the language setting for the ltex-ls language server.
I’m using the nvim-lspconfig and nvim-lsp-installer plugins (having used the latter to install ltex-ls).

Following these instructions, I did:

local lsp_installer = require("nvim-lsp-installer")

-- Create tables with changed server options if you want to deviate from the
-- default settings

local server_opts = {
    -- Provide settings that should only apply to "server-name" server
    ["ltex-ls"] = function(opts)
        opts.settings = {
        ltex =  {
            language = "en-GB"
        },
    }
    end,
}

-- Register a handler that will be called for all installed servers.
-- Alternatively, you may also register handlers on specific server instances instead (see example below).
lsp_installer.on_server_ready(function(server)
    -- Cpecify the default options which we'll use to setup all servers
    local opts = {
        on_attach = on_attach,
    }

    if server_opts[server.name] then
        -- Enhance the default opts with the server-specific ones
        server_opts[server.name](opts)
    end

    -- This setup() function is exactly the same as lspconfig's setup function.
    -- Refer to https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md
    server:setup(opts)
end)

I’m probably doing something silly, but I’m not sure what!

On that note, would it be possible to add multiple languages to ltex-ls, or switch the selected language easier than by editing the configs?

Any help would be appreciated! Thanks.