Use API in Microsoft Flow with HTTP connector Basic Authentication

[Eugene]

First you need Base64 Encoded API string: 

Example: you have org key "frdt1", instance key "sadf5" and API key: "teo957f8gmae0snzzzce5ma0i1cgax6j"

you need to Encode this string to Base64 (i.e. Read this to get those values:  https://github.com/sherpadesk/api/wiki#all-other-follow-up-requests)

{org_key}-{instance_key}:{api_token}  frdt1-sadf5:teo957f8gmae0snzzzce5ma0i1cgax6j
in base64 means:  "ZnJkdDEtc2FkZjU6dGVvOTU3ZjhnbWFlMHNuenp6Y2U1bWEwaTFjZ2F4Nmo="

 In Flow use the HTTP connector and set the Authentication as Raw. Under the Value place the Base64 Encoded API string.

More info: https://powerusers.microsoft.com/t5/Connecting-To-Data/Optional-password-in-HTTP-connector-Basic-Authentication/td-p/632754