Connect indicator with license manager (REST API)

I am looking for a skilled coder that can implement a secured continuous validation between my indicator and my license manager plugin for wordpress (by REST API). I have the documentation for the license manager plugin. 

The indicator must have an input to enter the license key which will be checked by status, let's say, every 15 minutes or so.

Whenever there is no internet-connection, the indicator does not work and displays the issue.

Whenever the license isn't valid (anymore) by , the indicator does not work and displays the issue.

I want full source so i can implement it in future indicators and expect that the code and the web-requests are as secure/encrypted as possible.

Shouldn't be a very hard job but i want it done by a skilled coder with experience in this field.