Is there a way to generate consistent characters using OpenAI's API with DALLE3 model, as DALLE2 image variation API doesn't provide satisfactory results, and custom GPTs are not available via OpenAI APIs?

I’m currently working on generating consistent images for my animated video project. I used a custom GPT called Consistent Character GPT to create consistent characters for my animated series. However, I want to access it via API. Since custom GPTs are not accessible via OpenAI APIs, I turned to the DALLE2 image variation API. Unfortunately, the quality of results from DALLE2 isn’t as good as DALLE3. Is there a way to generate consistent characters using the OpenAI API with the DALLE3 model? While I could use the Assistant API for this purpose, it doesn’t currently support DALLE3.