之前每分钟请求都不怎么报错，今天频繁报错 
错误：You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. * Quota exceeded for metric: generativelanguage.googleapis.com/generate_content_free_tier_requests, limit: 50 Please retry in 36.066495878s.