Open Instagram and go to the profile you want to identify
Check the username at the top of the profile
The Instagram ID is the username, not the display name
If you mean the numeric account ID, open the profile page source or use an Instagram ID lookup tool
Copy the profile URL from the browser or app share link
Use the username in the URL to identify the account
Search the username in Instagram search to confirm the account
Check tagged posts, comments, or mentions to verify the correct profile