I want to attach this modem to my RB201 router. Has anyone tried this? It doesn’t even detect it on /system resource usb print. Will I have to wait for an update to the MikroTik system?
Yes. it’s working pretty fine 
my ISP Newroz Telecom “Fast-link LTE”
AP name is Fastlink
no username and passwords.
If not detect, is possible that you have too old version of RoS. Please upgrade to newer, and follow the instructions posted before.