In Write a post, check which writing model is selected before starting. A Blog Site owner or admin can see the saved default and its billing source in Settings → Integrations → Writing model and billing. Your team can change the selection for an individual run where a model picker appears.
Look under Included with your plan → Writing to compare the available writing models and their displayed credit prices. Images is a separate list.
When two or more eligible choices are available, an owner or admin can open Change the default, choose a model, and select Make it the default. With just one choice, the change control is hidden.
Open Write a post and check the model and estimate before you start. Where the writer offers a model picker, you can choose a different model for that run.
See the writing model setup guide.