The general advise is to get this working in Postman first, then move what you have to the HTTPCaller in workbench.

If you have this working in Postman, please elaborate what you have and what does not seem to work, with a HTTPCaller printscreen where the token is blurred.

Looks like you're close, might be that you just need one set of {} and also looks like there needs to be a space between bearer and the token so:

bearer {token}

If that doesn't work remove the curly brackets all together and try again with

bearer token

The API doc also mentions something about a "Multi-Organization Token". If you are working with one of these then you also need to provide your Organisation ID

Solved using Postman, looking at the Headers details of GET. I see the exact format requirements for the HTTPCaller.Translated to HTTPCaller