Toolset & GeneratePress integration

If you're comfortable inside your database, then definitely. You can look up your post in the postmeta table, and grab the meta_key. That's what you add into the Page Header: {{custom_field.meta_key}}

Hi Tom i'm afraid its not gonna work as i have 100s of these meta_key.

you mean there is no auto fetch for toolset custom field ?

The template tag in the Page Header needs a specific key attached to it. I'm not sure how an auto fetch feature would work with that unfortunately.