Connecting guests to your Wifi
I suggested a couple changes to the part on how to do the NFC tag:
To write the tag, use the app NFC Tools to do the writing as it is versatile and needs no special permissions.
Using NFC Tools, use the Write tab, Add a Record to add these two records:
URL / URI: wifi:networkname/wpa/password
Then, write the tag.
Finally, presentation is a good thing. I've attached two sample files to this post showing sample text and a sample QR code. The PNG is a simple PNG file. The SVG file is an InkScape SVG file.