GTV Stage I - Endorsement - letter of recommendation

Hi community,

I am trying to switch from a skilled worker dependent visa to a global talent visa. I am still at the endorsement application stage (via the business talent in digital technology route) and I have some questions around the letter of recommendation.
How can I find out whether the recommender is an "acknowledged" person?
What are the exact guidelines for the letter of recommendation?
What should be the designation of these members?
Are there any examples around the same that can be referred to?

Thanks for your time!