So, you have a Sinclair Spectrum Next and an old Interface One and Microdrive - despite it really not being required due to the Next's SD/DivMMC interface it's an itch you need to scratch so join me in my quest to get new and old hardware to communicate.
Will it work?
Anyway in a clue if it worked or not here's a video that helped me sort it out: • ZX Interface 1 and 2 on the Spectrum ...