Power Users - Microsoft Power Platform
Microsoft Power Platform offers multiple solutions that can leverage APIs. Most solutions use custom connectors to connect to APIs, while some require a low-code solution.
PowerApps and Power Automate
Both Power Apps (canvas apps) and Power Automate use custom connectors to connect to APIs. For non-canvas apps, Power Apps API connectivity must be coded.

The Core API connector can be found here:
If there are any issues with the connector please contact the API team. For issues with Power Apps in general, please contact the KTG-ECM team.
Power BI
Power BI also uses a custom connector for custom APIs.

Using the custom connector in Power BI:
Download the file here
Copy the extension file into the
[Documents]\Power BI Desktop\Custom Connectors
directoryOpen Power BI Desktop
Note, to load extensions for use in Power BI, you will need to lower the security level for extensions in Power BI Desktop to enable loading unsigned/uncertified connectors.
Go to File | Options and settings | Options
Go the Security tab
Under Data Extensions, select "Allow any extension to load without warning or validation"
Restart Power BI Desktop