According to this page https://docs.z.ai/guides/overview/pricing, the GLM-4.5-Flash model is free, and indeed i was using it for free for a couple of days, but now when I use it with Claude Code I keep getting the following error:

  ⎿  API Error (429 {"type":"error","error":{"type":"1113","message":"Insufficient balance or no resource package. Please recharge."},"request_id":"20250923171253c12d96cad2d543ed"}) · Retrying in 4 seconds… (attempt 4/10)