Hello, Recently I encountered the problem of choosing an accesspoint with LTE for WiFi cameras. In my location, there are no interferences or high speed requirements, only about 10-20Mb/s. It would be best if it was external, but it can also be internal. Now a stupid question: would RB912UAG-2HPnD-OUT with usb lte modem meet my requirements. If not, what other model would you recommend?

Isn't the WAP LTE kit:
https://mikrotik.com/product/wap_lte_kit
the device more similar to your description/requirements?

Personally I would not trust a USB external modem on a device that is outdoor or however difficult to reach, and - besides - there could be compatibility issues.

I mean, if you already have the board or the modem or both It could be an interesting experiment and could save you some money, but if you have to buy them I think that is better to have an integrated device.

Yes you have right but now I have a lte modem and I like to buy Basebox 2 because I have offert with cheap price.

Really no idea if it could work, is the LTE USB modem you have compatible?

https://wiki.mikrotik.com/wiki/Manual:Peripherals

If it doesn't work and you need to use (as intended) a mini pci-e modem, then it will cost you more money.

I have compatible and tested on hap ac2 usb modem(Alcatel IK41VE1)

I agree with @jaclaz that wap lte kit is better suited for your needs just because lte usb modem is not really made to work outside where weather condition can be harsh. Really hot in the summer and really cold in the winter.

Nobody said it wouldn't work but question is how reliably. If budget is concern then if you tested device and it's working with ROS then go for it.