how to set the rootdir ?

[tendertree]

to avoid confilcts with deno. I try to set the root dir to "package.json" to apply this method

nvim_lsp.tsserver.setup {
  on_attach = on_attach,
  root_dir = nvim_lsp.util.root_pattern("package.json"),
  single_file_support = false
}

However, I don't konw how to set the root dir in default config

do I load tsserver config seperately ?