Syntax help. How to use Basic auth in headers of HTTP Request

[SuperTempAccount]

Hey there,

I'm using the HTTP Request block to create a post using the Wordpress API.

The header block looks like this

I get a 401 authorization error.
I know the details I have are correct because I can post using curl with the same details.

These are the syntaxes I've tried
"Basic xxxxtokenxxxxx"
Basic xxxxtokenxxxx
!!Basic xxxxtokenxxxx
{{secrets.mytoken}}

None of these have worked.

Any help?

Thanks!