As of 17th Nov 2023, foreign nationals from 54 countries are eligible for 72/144-hour visa free transit policy holding interline tickets to transit to a third country or region via ports and cities in Chinese mainland. Please see https://en.nia.gov.cn/n162/n227/c117540/content.html for details.

Please note:
If the validity of your passport or your travel document is less than 3 months,
if you've ever been stamped for a visa rejection on your passport,
if you've illeagally crossed the border of China, illeagally stayed your visa or permit, or illeagally worked in China,
etc...
China Immigration Inspection will not approve your entry permit.

Links:

144-hour Visa-Free Transit in Beijing
https://english.beijing.gov.cn/travellinginbeijing/144hourvisafreetransit/index.html

144-hour Visa-Free Transit in Guangzhou
https://gz.gov.cn/guangzhouinternational/home/bulletin/content/post_9254377.html