Just an FYI to others. In the OpenAI documentation at https://platform.openai.com/docs/guides/rate-limits?tier=tie... it looks like once you are on Tier 3 or higher, then you can get access to o3-mini.

However, it looks like only select users are granted access and access is given in batches (see https://community.openai.com/t/usage-tier-3-access-denied-to...). Just something to consider.