Any alternative of openTextDocument({langage ...

[Freed-Wu]

        /**
         * Opens an untitled text document. The editor will prompt the user for a file
         * path when the document is to be saved. The `options` parameter allows to
         * specify the *language* and/or the *content* of the document.
         *
         * @param options Options to control how the document will be created.
         * @return A promise that resolves to a {@link TextDocument document}.
         */
        export function openTextDocument(options?: { language?: string; content?: string }): Thenable<TextDocument>;

coc.nvim seems not to support this API. Is there alternative method?

[fannheyward]

No such API yet, coc.nvim has workspace.openTextDocument, but this is used to open an exist file with file uri.