Using an App on HP (HP newbie question)

OK. I am sure that I am just plain missing something, so I apologize for the stupid question. But my searches have found nothing (probably because this is so basic).

I am migrating from ST to HP, have gone in and added two Apps (Google Next and TP-Link Kasa). The apps are right there in Homey, no problem. But I was never asked to login to my existing accounts and I cannot find anywhere to do so.

Now, perhaps I am still stuck in a ST mindset. Under ST I would link to the online service for the devices - ST communicated with those services. Does HP not do that and connect directly? As in, does the App on Homey mean that you can directly connect to the device? If so, do you delete the device from the manufacturer’s app first?

After installing the apps, have you tried to actually add a device for one of them? That’s usually when you’re asked to authenticate (only for the first device). Both Google Nest and Kasa rely on cloud services, also for Homey, so there’s no local control.

Ah. That makes a lot of sense. I knew it was something simple. I was just used to ST, who requires you to authenticate when you add the service - while HP waits until you add a device to do it.