使用ElevenLabs API生成长文本语音时频繁出现401未授权错误求助

我在测试ElevenLabs的API时，发现生成较长文本（超过几个单词）的语音时，仅偶尔能成功，大多数情况下会返回以下错误：

Error: 401 Client Error: Unauthorized for url:
https://api.elevenlabs.io/v1/text-to-speech/h1YH6feHIpk966qs5vt1/stream

我猜测这可能与某种按时间或字符计算的限制有关，ElevenLabs官网提到有2500字符的限制，但我在API文档中未找到相关说明，请问有相关经验的人能解答吗？

我的代码如下：

from elevenlabslib import *
import os

def get_path():
    return input('Path: ')

user = ElevenLabsUser('<API_KEY>')

voice = user.get_voices_by_name('Adam')[0]

text = 'In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees.'

path = get_path()
while not os.path.exists(path):
    print('Path does not exist')
    path = get_path()

path.replace('\\', '/')

if path[-1] != '/':
    path += '/'

name = input('File name: ')
if name[-4:] != '.mp3':
    name += '.mp3'

with open(path + name, 'wb') as f:
    f.write(voice.generate_audio_bytes(text))
    f.close()

内容的提问来源于stack exchange，提问作者bob0815