Your EIN (tax ID) is 81-2908499. It belongs to The Hack Foundation, the 501(c)(3) that fiscally sponsors your project, and you can share it with donors and funders.
What an EIN is
An EIN (Employer Identification Number) is the IRS tax ID for an organization. Because your project is fiscally sponsored by The Hack Foundation, you use its EIN. You can tell a supporter that you're fiscally sponsored by The Hack Foundation (Hack Club).
Where to find it
The EIN is also listed at the bottom of hackclub.com and on Hack Club's branding and legal pages.