How do indie/open-source projects get a WCAG ACR done affordably?

I built a completely free forever open-source productivity Application called NoSuggest and featured it in HN community. Now recently I have implemented keyboard navigations, skip links, modal focus trapping, screen reader support and prefers reducted motion. The accessibility statement is published in https://nosuggest.com/accessibility.

I am planning to apply for CAST/Digital Promise's Accessibility Baseline certification. It is required for a formal badge in ISTE EdTech Index listing. Facing a blocker as they require a third party WCAG 2.1 AA conformance report (ACR/VPAT). Self assessment won't qualify for it.

This is a single page app with no login. Approx 8 screens and minimal scope. Professional audits would charge couple of thousands of dollars. For a permanently free tool, it is not a viable option.

Has anyone navigated this for a free, open-source project? Anyone can volunteer to review?

Thank you.