Handbook page 105:

DA, Line Out 3-8, rear
[...]
Output level switchable Hi Gain, +4 dBu, -10 dBV

Try then lower output level of -10 dBV.

What Mixer and what is the type of input. Analog input or Mic input ?

XLR plugs can be applicable to both, Mic inputs and symmetric line inputs. When looking to the specs of several of their products, then it appears to me, that the XLR inputs can be used for Mic and Line.

Same like with the RME Octamic XTC, you can connect either 8 Mics, but can also use these inputs for balanced lines.
RME automatically detects this, I am not sure, whether you need to configure the input to be for Mic or Line.

This I deduce from their Specifications overview on product web page (sorry no link here, their webserver has no static link to it, too much scripting instead of a copy / paste-able URL :-/).

TouchMix-30 Pro
Inputs     32 (24 mic/line, 6 line, 2 stereo USB)
Mic/Line   24 (20 XLR, 4 XLR combo)

TouchMix-16
Inputs      22
Mic/Line    16 (12 XLR, 4 XLR combo)

TouchMix-8
Inputs      14
Mic/Line      8 (4 XLR, 4 XLR combo)

Look at your manual, contact the seller, contact the vendor or ask in their user forum to double check.

For me it looks as if you only need a TRS to XLR cable between UFX and your QSC mixer for a balanced line connection like i.e. this here: https://www.thomann.de/gb/cordial_cpm_5 … ImVuIn0%3D