API connections middleman

I have 3 API endpoints that need to work together to move contacts from marketing campaigns to CRM.
The logic process is as follows.
A potential Lead clicks on a PPC campaign to enter a website an then submits a form.
The API 1 Needs to transmit the data to API 2.
API 2 recieves the lead data. The AP2 will then respond with a client ID if it's already in the CRM
If you recieve a reply for API2 you then need to take the client ID recieved and add that client ID to the new payload and push the same lead information (with the client id from API 2's reply) to API 3




API Information below:

1. API 1-A restful API that delivers contact data from marketing
2. API 2-A "New Lead" end point that needs to receive "New Contact" data from API 1 and then
3. API 3-A "contacts" endpoint for exhisting clients

White Paper for:
API 1 - https://reachlocal.github.io/api-docs/?java#crm-integration-get-contacts-for-an-advertiser
API 2 - https://documenter.getpostman.com/view/6050361/S11RLvu1
API 3 - https://apidocs.sherpacrm.com/#94a6bec5-a6e1-4332-a154-ec9091313409