I need to know how exactly one goes about using WAB custom widgets and themes in web apps made and hosted in AGOL and Portal. I have read that it is not possible to use custom components in AGOL. Is this true for all versions of AGOL? Is this the same with Portal? My organization intends to make web apps in Portal and host them there, so this is particularly what I am concerned about. I don't want to invest the energy to learn how to make custom themes and widgets, and end up not being able to use these skills for my organization's projects. So is it possible to use custom widgets and themes in web apps hosted on AGOL or Portal, Portal in particular?
Thanks for your help