Custom Map Marke Icon – Upload does not work

Hello,
I am so sad because I did upload my own Icon and the Picture is to see on the admin site but not on my map. There is the Default Icon or if I did choose another from catalogue that one.

So what is wrong here ?

http://www.biketags.de/dealer/

Please, please, please help me one time. Thanks a lot.

https://ww.wp.xz.cn/plugins/basic-google-maps-placemarks/