Sim800L Low Signal capacitor,antenna connection or code to be blamed?

Hello all and Ravi .

I will try to express my problem as simplest.
I believe that i have almost finish a project to send data to thingspeak
every somehow…(weight of beehives)

When i am in a big city like Athens ,that i am programming and testing its all good.

The problem starting when my cousin(‘client’ our case)
goes to the field very far from big city with low signals.

Then …sometimes the project sending the data but most of the times
failing…most propably by the signal.

My question is…and because i am new to electronics and i dont know nothing…
-Am i sure that the signal is the problem?
-Or maybe the problem is that we need capacitors in order to ‘face’ the failure (low) signal ?
-Or even maybe in my code i must delay more after i give the HTTPACTION command …in order to give it time to send the data?

And ofcource my antenna connection is NOT good
but the thing here is that ican not blame my self for my not good antenna connection because here in city…i have not problem.

In a week i will get back my arduino-sim800l box
so that i am asking here in case of someone wants to

“turn my thinking” in one of above REASONS for the problem
not only to not loose time…but to not mess with all things and make them worst.

So if anyone can suggest to me from where i most propably
must start to debug my project …it would be nice help.

Just for the case i a thinking firts to try installing 1-2-3 capacitors of different uF …just because i am really not elecrtician…and just that i want to ensure for this…

If you think that capacitors HAS nothing to do with the signal …PLEASE NOTE this to me in your answer …so i can focus
on antenna connection and my coding.

I hope that i explained as i could.
Thank you in advance and you can find my …almost finished project… in my jimakoskx.blogspot…com.

I wrote it like this because i dont want someone thing
that i amadvertising …and in reallity i just asking some help…

Thank you…

PS…here is my structure

OK…all…i solved it by adding a 3300 capacitor.

Now works without antenna at signal db=4 !!!

And with antenna …of cource and the signal goes to 21 !!!

Thank you all…I will add here further notes when i test also in the field !!!