Connecting spring antenna to sim800c/l

How should I connect the spring antenna to this sim800c module?

Is it welded?

Screenshot 2017-07-19 10.05.42.png

Screenshot 2017-07-19 10.05.42.png

Solder? To the square pad bottom right in your image.

You can see that there is a fine trace from the external aerial connector to this pad.