First thing first, microSD (TF card) and microSIM card (Sim card) are two different things 
Second, the AX1800 (Flint1) the AXT1800 (Slate AX) are NOT cellular routers (4g/5g routers) aka routers that use mobile operators waves to serve you a wifi connection, for that look at:
GL-X2000,
GL-XE3000,
GL-XE3000,
GL-E750,
GL-X750,
GL-XE300,
GL-X300B
Hope this helps to clarify 