Solved, courtesy of Free tier is dead? thread. The wording of legacy hobby plan in my profile has not been brought up to date. There’s a minimum $5/mth charge.
or not? Fly.io Resource Pricing · Fly Docs says:
Legacy Hobby plan
If you were on the free Hobby plan at the time that the paid Hobby plan became the default for new organizations, your plan is now called the Legacy Hobby plan. Your costs stay the same as they were, with no monthly subscription fee, and no included usage beyond the free resource allowances.
If you change your plan, you won’t be able to return to the Legacy Hobby Plan.
Emphasis added. I’m confused again. What free allowances?