OP should just calmly tell OpenAI that they are not infricting on the trademark, because it's not in the same business domain. OP should not communicate with O

OP should just calmly tell OpenAI that they are not infricting on the trademark, because it's not in the same business domain. OP should not communicate with OpenAI without a lawyer at this point. The one exception is if this vaguely threatening letter turns into a formal cease and desist, and OP cannot budget for a lawyer.