You may explore the http_request (GET) and http_request_post (POST) plugins to send an HTTP request to your API's and convert the response into a table.
Please note that it’s disabled by default for security reasons, I would highly recommend reading the documentation very carefully before you try it as the plugins allow queries to send data and the user's security token to external user-specified network endpoints.
Here are sample query examples for reference:
http_request (GET):
let Uri = "https://prices.azure.com/api/retail/prices?$filter=serviceName eq 'Azure Purview' and location eq 'EU West'";
evaluate http_request(Uri)
| project ResponseBody.Items
| mv-expand ResponseBody_Items
| evaluate bag_unpack(ResponseBody_Items)
http_request_post (POST):
let uri='https://example.com/node/js/on/eniac';
let headers=dynamic({'x-ms-correlation-vector':'abc.0.1.0', 'authorization':'bearer ...Azure-AD-bearer-token-for-target-endpoint...'});
evaluate http_request_post(uri, headers)