[Bug on sms ping]fail to send request message display when trying to send ping

Expected behavior

SMS ling is an open source app which is used to send ping message,the application does not require rooting the device

Actual behavior

I uninstalled the app and reinstalled it, but unfortunately, the same problem still occurs, I can't not send SMS ping using the SMS ping application

How to reproduce

• download prayer times app from f-driod application. (see link to download directly from f-driod below).
  https://f-droid.org/app/com.itds.sms.ping

• open application.

• goto space provided and type in the mobile number you want to send the ping to and press send.

• the app displays fail to send request.

• version of the application : v 4

• last updated : 10/04/18

• Browser:f-driod / sms ping
• Operating system:Andriod 7

Recording Of The Bug