How setup RB912R for DDNS

RouterOS Beginner Basics
1

Hi,

Please help, i have a RB912R-2nD-LTm&R11e-LTE, with win box v6.42.1

I have RB912R on remote location, with dynamic IP.
How setup DDNS to access remotely?.
Also, how setup LTE / GSM sim card?.

Does DDNS have a annually charge?.

Regards,