Ask HN: Retool, Budibase, Tooljet alternative for enduser widgets?

Looking for product, open source preferably, like Tooljet, retool, etc. but also lets you drop a widget into a customer facing app like a webapp that is password protect. The closest one I found might be Budibase.

I like the idea of building back end tools but sometimes that backend tool needs to be populated by end users on a webservice.

I'd like to be able to just drop it in as an embed widget or js code.

Anyone know anything like that?

Thanks