I'm using prestashop 1.7. and I'm trying to make an external payment gateway where i have been provided with api url, request response, api key, password etc. I have made till the configure page but have no idea how to proceed further inorder to redirect my customers to gateway page and then return them back to order page based on order success or fail. I have no idea where to place request response or what is the correct way to write since I'm new to presta. Can anybody help me with this problem? It will be a big help for me as I'm stuck for almost 3 days now. I will share the code for better understanding if asked. thanks in advance!