https://www.napa-net.org/secure-act-tax-credit-qas
Found this with the applicable Q&A shown below. Note that 2.0 just expanded what was available on this.
Q3: How do not-for-profit organizations receive the 403(b)-start-up credit for offering new plan? Is the credit applicable to non-profit organizations?
A3: The credit is not applicable to tax-exempt entities because it is not a refundable credit. Therefore, the credit is not available for the adoption of a 403(b) plan. The types of plan that can qualify for the credit (for plan sponsors that are subject to taxation) are qualified plans under 401(a), annuity plans under 403(a), simplified employee plans under 408(k), and SIMPLE plans under 408(p).