External Web API call from Appian

Hello Sir,

I want to develop solution between Laserfiche ( ECM software ) and Appian.

In current requirement , I want to move some of the documents from Appian system to Laserfiche repository.

I have developed API with all parameter which included files bytes and we will parse that bytes and create document within laserfiche repository,

My question is how we will call my web API from appian ?  I am completely new with this kind of intergation.

I would aspect someone also guide me best way do it.

Thanks,

Pratik