How to setup BTP Destination with Document Translation API at SAP Translation Hub

[shbaek]

Hello.

First of all, I am new to the SAP BTP system, so I am not familiar with the understanding and use of the system.
I'm now trying to make a demo application that translates other language documents by Build Apps.

So I designed the flow as follows.
Connect Document Translation API to BTP Destinations,
Connect Destinations to Build Actions,
finaly I would like to make the Application by Build Apps.

However, when I tried to connect Document Translation API to BTP Destinations, I found that the OAuth2.0 Application Flow used by API was not in the Authentication option of BTP Destinations.

I'm currently applying Authentication to Destinations based on the elements used to set up the API's Environment, but I receive a response such as "401 Authentication Error" when conducting a connection test.
(I check that it's working when the terminal sends a command with a header and body through the curl command, but we used the bearer as Authorization at this time.)

I've tried many things, but the problem hasn't been solved, so I'd like to ask for your help.

Thank you for your help.

[shbaek]

I searched more about that, some document says OAuth 2.0 Application Flow is same as OAuth2ClientCredentials option. OAuth 2.0 Application Flow is also called Client Credentials Grant. And the technical implementation of Client Credentials Grant in the OAuth 2.0 standard is called OAuth2ClientCredentials. Is this information correct?