Check out the footage ... both Mike and Roy were all smiles when they officially signed on the dotted line last month during a Zoom call.
Our sources tell us Triller -- a social media app looking to overtake TikTok -- shelled out roughly $50 mil for the rights to the fight, looking to make a statement that they're serious about moving into the live events space.
Mike says he's personally not getting rich from the fight -- saying his cut will go to charity ... "I'm not getting anything."
Tyson says his mission in life isn't to amass wealth -- it's to help people in need, and doing this fight was a great way for him to make an impact.
As for Roy, he tells us the way his contract is structured, he has the potential to rake in more than $10 MILLION for the fight, as long as the PPV numbers are big.
Roy says he can make more money at 51 years old than he did when he was 31!
As we previously reported, the epic matchup is set to go down in California on Sept. 12 -- with no fans in attendance due to the COVID pandemic.
8:33 AM PT -- Tyson's reps contacted us to clarify what Mike told us regarding his fight paycheck being donated to charity.
"Mike is committed to charitable causes at this stage in his life. Mike is making a substantial donation to charity to help those effected economically, medically and socially by the pandemic. The exact amount will be determined after the bout"