Can range extender AC750 give static IP addresses to client?

@wiiNinjaOne  Hello, 

Range extender doesn't support assigning a static IP address for clients, you will need to set up static IP manually on those clients, e.g. set up static IP for Windows: 

https://www.tp-link.com/support/faq/41/

For the device working in a fixed location ( do not need to move or roam between RE and router)

You could reserve an IP address for it on the router using the virtual MAC address showing up on the RE's client list, below FAQ for reference:
https://www.tp-link.com/support/faq/2019/