Please review the magic link article. This article will discuss how to configure the magic link "server" endpoint. This server should tell OpenWater if a particular user is allowed to access the platform.
In summary you need to create an HTTPS based endpoint that accepts a querystring email
This should return a JSON object with the following properties
isValid: true/false
firstName: nullable string
lastName: nullable string
company: nullable string
thirdPartyCorporateId: nullable string (used to tie this user back to someone in your AMS)
externalAuthData: nullable string (this string can be reported on and filtered on inside OpenWater)
You can specify one or more External URLs. OpenWater will request them one at a time until one reports isValid: true.