I want to create a request form where users can select an object from a predefined list or type a new object if it doesn't exist. and its create a new object.
Assist (or previously known as Halp) doesn't support all types of fields. See the documentation here.
I'm afraid you cannot achieve this yet with Assist in Teams or Slack. You would need a custom field of type Assets object in the first place, which is not yet supported by Assist. You'll also need to be on the Premium plan of Jira Service Management in order to use Assets.
I also don't think I've ever seen any reference or evidence of customers being able to add new objects to Assets.
You'll have more success if you present your form not in Assist (Halp), but in the Jira Service Management portal. Then, you can use a third-party marketplace app that can do the trick of selecting existing and adding new objects. There are a couple that may integrate with an external database to present and manipulate options.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.