BOXER 2.2 HDI 2013. - Does not start, no reaction to turning the key

I warmly welcome. I urgently need your help. The car is rarely used - in the last 4 months it was literally a few times. On Thursday, I started the car a few times (I can't find the mother-second key, working time about 20 minutes). Unfortunately, for the next day he didn't want to fire up. Symptoms: after inserting the key and turning to I everything is normal (the counter and standard lights are on, etc.), after turning to turn on the engine no reaction (same as in the first step).
The key light is not on, CODE is not on, does not turn, does not start. I checked the fuses in the engine compartment (they are OK), I did not check the relays (I don't know how to check if they are good), + and - on the battery also checked.
The car is 100% accident-free (I have it from new), mileage 270k, power 130KM. The first time something like this happened to me.
Could someone please help me? Do the symptoms indicate anything?

Thank you in advance for your help.

A rarely used car = a discharged battery that does not have the power needed to start the engine. What voltage do you have on the battery?

robig wrote:

A rarely used car = a discharged battery that does not have the power needed to start the engine. What voltage do you have on the battery?

there is a lot of electricity in my opinion - everything works, radio, windows, airflow, lights, controls do not dim
he fired on the push - I think it's an alternator
I wonder if there is an alternator to replace or rather some connections or a plug

More like a starter, not an alternator.

adam7009 wrote:

More like a starter, not an alternator.

my error - yes, sorry for the mistake, starter of course