They aren't? Not only is the idea of mass Uyghur slave labor atrocity propaganda akin to claiming that there's "white genocide" in South Africa, Christian genocide in Nigeria, or that Hamas sexually assaulted babies in Operation Al-Aqsa Flood, but the PRC is an incredibly industrialized country and as such doesn't have a need for slavery. Slavery in general is a horribly inefficient system fir anything other than agrarian production, which is why the Statesian North liberated the slaves in the south, for more wage-laboring industrial workers.

In the case of Xinjiang, the area is crucial in the Belt and Road Initiative, so the west backed sepratist groups in order to destabilize the region. China responded with vocational programs and de-radicalization efforts, which the west then twisted into claims of "genocide." Nevermind that the west responds to seperatism with mass violence, and thus re-education programs focused on rehabilitation are far more humane, the tool was used both for outright violence by the west into a useful narrative to feed its own citizens.

The best and most comprehensive resource I have seen so far is Qiao Collective's Xinjiang: A Resource and Report Compilation. Qiao Collective is explicitly pro-PRC, but this is an extremely comprehensive write-up of the entire background of the events, the timeline of reports, and real and fake claims.

I also recommend reading the UN report and China's response to it. These are the most relevant accusations and responses without delving into straight up fantasy like Adrian Zenz, professional propagandist for the Victims of Communism Foundation, does.

Tourists do go to Xinjiang all the time as well. You can watch videos like this one on YouTube, though it obviously isn't going to be a comprehensive view of a complex situation like this.

Can you provide a source for that claim?

What does this even mean

Big if true

you are literally sniffing so much glue that your mind exists on another plane of existence