Multiple wi-fi credentials

How do I setup multiple Wi-Fi credentials, so every time I move to another Wi-Fi spot DietPi will connect to it itself?
Also, if I don’t get the Wi-Fi available at that place, then I’m plugging in the ethernet cable, but most of the times it does not autoconfigure via DHCP.

Before DietPi I could use wpa_supplicant, but here we have GUI for that and advised NOT to edit this file manually.

Thanks!

Your wish have become true since DietPi v159: DietPi/CHANGELOG.txt at 5cc4e59a128ff3998802e4a80fa5751d11f7a88f · Fourdee/DietPi · GitHub

you can do what ever you want to do, but if you edit configs by hand, you can’t use menu (GUI) for setup your wifi any more.
And some dietpi-software, like WiFi-Hotpot or TOR-Spot, which depends ain dietpi-config defaults, will not work any more.
So you will be alone now …

Great, thanks!