Can anyone help how to link over the square loyalty and gift to micros res 3700 using donet sdk
You’ll probably need to reach out to Micros for assistance with any migration to their system. 
I would if I wanted to migrate however that wasn’t my question
What are you wanting to do then? Micros isn’t a supported device or system we integrate with. Would you mind sharing more about your use case?
Being able to accept square gift cards through micros and integrate loyalty would take a developer a couple of days to write the code would also open square up to billions of potential customers