I was using the API key on the Codex CLI to go around the rate limits.
Unfortunately, I signed up to the business plan thinking I was going to be able to use the GPT 5.3 codex Spark. However, that is not the case.
Now I want to know if there is any option to convert the business plan that is paid into platform API credits, or if there is any way to enable the Spark model on the business plan.
It is explicitly available on Pro from day one, but I believe from the wording that you do get to use at some stage on Business (see “API”), but you may have to advance some Tiers to get access: