404 errors when trying to run user management APIs

I am getting 404 error when trying to run an API via Postman to get user information. The same API works fine when I run it against another Okta preview tenant. Also other Okta APIs seem to work on my tenant (e.g.https://dev-916711.oktapreview.com/api/v1/apps?filter=user.id+eq+“00ugisjj7htdAXO570h7”).
Is there some flag that I am missing, CORS configuration etc. to make this work?
Here is the API that I run:
GET /api/v1/users/{{MyUser}}@gmail.com
Host: dev-916711.vidmpreview.com
Accept: application/json
Content-Type: application/json
Authorization: SSWS {{My Okta API Token}}

Response from Okta:
404 Not Found
and the error is:
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