Creating a WEP Hotspot from iPhone 7 through MacBook Air?

Hi. I have been trying for a few weeks now to connect my old Nintendo DSi to a new WiFi DNS. However, it requires a WEP password and I don't know how to do that.

I tried to open a hotspot on my iPhone 7 which is detectable by Bluetooth (and I had bluetooth on my phone and MacBook, with the two devices connected).

I then went to sharing in system preferences and tried to share wifi from Bluetooth PAN to devices using WiFi (the DSi or 2DS, I have both) with the WiFi Channel being on Channel 1.

I start the sharing, but when I try to search for a WiFi on my DS I only find iPhone which it cannot to connect to as it is not WEP.

Is there a way to create a WEP hotspot through an iPhone 7 and MacBook Air that the DSi can connect to?

Any help would be greatly appreciated as I've spent so many hours trying to get this to work!

Kind regards,