I not know why I write this but... maybe you really need that how to, step by step instruction.
I just go to documentation at
https://wiki.mikrotik.com/wiki/Manual:I ... N_profiles
You need a computer with Windows, download WinBox from mikrotik.com/software.
Power your device by PoE Adapter and Injector.
Connect to RouterBoard like RBLHDR per WinBox.
Best way is discover your RB via Neigtboards tab, select Mac Address or IP Address and press Connect.
Remember to change add new admin and remove default admin in future.
The Easiest way:
Press QuickSet, type proper APN and press OK.
In this scenario you can provide PIN but you not select any Auth like PAP/CHAP to use Username&Password, you not specify other APN details. This should work in general.
More Manual way.
Prepare your APN settings, you can do few version here. One of them is Default.
Go to Manu Interface > LTE tab > LTE APNs button (Step 1,2,3)
LTE APNs window give you option to edit default one setting or create additional APN settings or 2x click at default one and by Copy button you can create few APN Differ Settings Policy - for e.g. when your SXTR have 2 SIM slot and then you want have two APNs settings for SIM-A and SIM-B.
I show you edition of default one, 2x click on it and see the new "LTE APN <default>" (Step 4)
Name - it's name, each one APNs settings should have differ name.
APN: - here you put your APN name e.g. RESELLER. In EMEA\EU we use "internet" who works for 90% ISP/MNO on market.
IP Type: in 99% you want this IPv4, you can ask your ISP/MNO what IP addressation he give, IPv4 or IPv6 or maybe both. You can do few APNs and check each one by one or change your default one.
Use Peer DNS - use DNS server from ISP/MNO - recommended because when your $ =0 then some MNO/ISP open you some hotspot page with information like "Agree paymants in 3days" etc. You can disable this but you must go to IP > DNS and put some own DNS servers like 8.8.8.8 etc.
Authentication: = none -> means Username&Password are not set and not check. Some ISP give you PAP or CHAP auth method still without username&password and some other give PAP|CHAP with some specific username&password. Many ISP/MNO give differ offers and settings.
OK button -> Allow+Close action in one button. Please not click Allow+OK who do 2x Allow action.
Assign your one or few APN Settings to lte1 inteface
Open WinBox menu Interface > LTE tab > 2x click on your lte1 interface (Step 1,2,3)
Select in APN Profile list and select one of prev. created , or only one default one field and press OK button.
Done.
You can see litle arrow at right of APN Profile: - yes you can select e.g. 2x APN at the same time and if Your ISP/MNO is ok with that you can receive 2x IPv4 or other configuration.
I hope this help you.