It is possible to directly power ATTiny85 3. But any minimal slow down in turning the hand power generator  crank handle immediately resets the ATTiny85. I was never able to pass the initial 5s pause before sketch begins to run. I remembered step up boost converter  and gave it a try. As you can see I passed the 5s phase and the 2nd LED got lit, but then I was not quick enough and the ATTiny85 did reset. But after that and after another 5s pause the 2nd LED get on and off 5 times!
 https://www.aliexpress.com/item/1set-J190-Model-S2-Mini-Hand-Generator-Popularization-of-Science-for-Teaching-and-Experiment-DIY-Hand/32754582227.html  https://www.aliexpress.com/item/0-9V-5V-to-5V-600MA-USB-Output-charger-step-up-Power-Module-Mini-DC-DC/32551686634.html  https://www.aliexpress.com/item/Digispark-kickstarter-development-board-ATTINY85-module-for-Arduino-usb/32584084654.html
Here is the youtube video: https://www.youtube.com/watch?v=bMX-IVWCnmo