Fault-finding SMS

Good day

Trust you are all healthy and well.

V13.27.1

I have configured my SMS-settings best I could based on API docs of the service provider.
ERPnext reports that the sms is sent but it is not getting at the service provider.

Does ERPNext log the URL sent out somewhere so that I can see if the URL was constructed
correctly ?

I had a look in /frappe/logs but could not find anything
I also looked in /var/log ( as SU )

If someone could offer some guidance ?