Hello Rohan ,
Yes, there is a REST API available to ingest custom logs and events into Application Insights. You can use the Application Insights core telemetry API to send custom events and metrics. This API allows you to track various user actions and monitor performance by sending telemetry data from different types of applications, including device and desktop apps, web clients, and web servers.
To get started, you need to add the Application Insights SDK to your project and use methods like TrackEvent to log user actions or other events.
References:
Please check if it helps you
Thanks
Deepanshu