Problem setting up Routerboard 911 Lite5 ac as AP bridge

I am using the RouterBoard 911 Lite 5 ac.
I would like to set this up as ‘ap bridge’ mode. But it gives an error, see pic attached.
ap_bridge.JPG

The error message says it all. Your device ships with level 3 license (CPE), whereas you need at least level 4 license to operate in the AP mode.

You can use it only in bridge mode to connect another device as station

how can I upgrade to 4 license?

So can you suggest a Routerboard device that I can use, my use case is the following:

Routerboard is connected to a router and creating a wifi from it? The IPs assigned to devices on wifi should be given by the router (not wireless card).

You have to buy another license http://wiki.mikrotik.com/wiki/Manual:License

Where do you plan to place the routerboard?
At home or in external environment?

In office/ conference setting

How many devices you plan to connect as wifi clients?
How far you will have clients from Access Point?
There are obstacles?

3-4 device. 10-20 ft away. no obstruction. But we do expect a lot of noise from other wifi networks.

The interference should be a problem if most of the channels are occupied.
In 2.4 GHz there are 3 non overlaping channels. 1, 6 and 11.

For 2.4 GHz or 5 GHz you can use:
https://routerboard.com/RBGrooveA-52HPn or https://routerboard.com/RBGrooveGA-52HPacn

For 2.4 GHz
or https://routerboard.com/RBcAP2nD
or https://routerboard.com/RB941-2nD
or https://routerboard.com/RB951Ui-2nD
or https://routerboard.com/RB951Ui-2HnD