Demanded ???UNDERSTAND my point....
In terms of demanding endorsement deals - the musician must demonstrate they have something to offer the manufacturer. In the past that was notoriety through popular albums, well attended live shows. In the past 10-15 years add in an active and well supported social media presence.
You won't be treated 'seriously' if you just think you are good, with no independent evidence to back it up.
We don’t know how that deal happened??