Wordpress API development

Hi, We are looking for API development to connect the website built by wordpress with an DRM(Digital Right Management) API. Please see the attached details. Please provide a quote/proposal with 1. Total cost, required delivery duration (hours/days), and 3. When can you get started if we placed the PO to you

Here is the website required API for integration: www.richestlife.com

Here is Vitrium API Guide: https://www.vitrium.com/hubfs/support-pdfs/Vitrium_API_Guide_for_User_Authentication_Authorization_and_SSO_v3.pdf