Selling house with shellys inside

I've installed five shelly 2.5 in my house and is all almost working perfect to control my windows shutters.

However I intend to sell my house and I do not know how the new owner can configure the shelly to a new router and new account.

Can someone help me?

Thank you.

I just had an idea, since the new owners are not tech savvy:

I will left in the house a old router connected to the shelly's and I will leave the username and password for the app.

Then the new owner just have to connect to the routers wifi network and use the app to control everything. Later if they desire they can just plug the internet modem to this old router to control everything remotely or even ditch the router and configure everything as they please.

Cheers.