How to connect 3th flow sensor to Profilux 3.1T ex

I have two PL-LY splitter.
The first splitter I connected to "Level 1&2" socket. And connect two flow sensor there. It works OK.
The second splitter I connected to "Level 3&4" socket. And connect level sensor ( it works OK ) and trying connect 3th flow sensor.

The GCC does not see 3th flow sensor. It can only 1 and 2 choose at the page 'Profilux - Flow-sensor'.
There are only 1 or 2 to choice on the 'connected at level sensor' column

How to connect 3th flow sensor to Profilux 3.1T ex?

Unfortunately the 3th level input can´t be used for a flow sensor, you need a level expanison card for that. From the manual of the PL:

Quote:

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4 Flow
You can connect flow sensors to the ProfiLux. They can be connected to the built-in level-inputs 1 or 2 and to
expansion cards with level-inputs.
Up to 4 flow-sensors can be connected to the ProfiLux 3-models.

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As you can see, level input #3 isn´t named.