How I can attach attribute with dynamic value when new paragraph is inserted?

5 
  /**
   * A function used to compute the attributes for the node or mark
   * created by this rule. Can also be used to describe further
   * conditions the DOM element or style must match. When it returns
   * `false`, the rule won't match. When it returns null or undefined,
   * that is interpreted as an empty/default set of attributes.
   *
   * Called with a DOM Element for `tag` rules, and with a string (the
   * style's value) for `style` rules.
   */
  getAttrs?: ((p: Node | string) => { [key: string]: any } | false | null | undefined) | null;

That’s because its a {tag} parse format and not a {style} parse, I think.