Google is always your friend:
You might want to check with the people who made the rules:
Interim Clinical Considerations for Use of COVID-19 Vaccines | CDC
Interchangeability of booster doses
Heterologous (mix and match) booster doses can be used in eligible recipients aged ≥18 years (see Considerations for use of a COVID-19 vaccine booster dose for more details).
And from here:
So you got the Johnson & Johnson COVID vaccine: What a booster means for you - CNET
The CDC says everyone who got the one-dose shot can get another dose of Johnson & Johnson at least two months after they were vaccinated, or they can get a booster shot of Pfizer or Moderna. That's because the CDC and US Food and Drug Administration have also authorized a heterologous booster dose for all adults who qualify for one, meaning people can now "mix and match" vaccines for a booster and aren't tied to their original vaccine.