Added proxy field and fix interaction with DOM (#288) * Added proxy field * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * docs: use_dom_submit is obsolete * core: use better selector for error handling --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>