Many IDCs have free VPS.

Domestic Baidu Cloud, Tencent Cloud, JD Cloud, Western Digital, and Jing'an are generally free for 15 days or one month, but they all require real-name authentication.

Foreign Google Cloud and Amazon Cloud are also free, but generally require a foreign credit card.

Of course there are some VPSs that are free, but not often. You can follow the blog of VPS primary school students, there are often free VPSs to share