Because it doesn't say it. It instead lays out a series of new designations and powers handed to the President. Specifically the President can now designate new kinds of national security threats and demand various mitigations to stop them. Anyone who does not obey is facing fines and prison time.

So for example, President Biden could designate TikTok a national security threat under the RESTRICT Act, and then order VPN companies to block outbound traffic to TikTok. If the VPN companies refused they would be liable.

Don't blame yourself for not finding it, I had the same reaction last night. The libertarians who caught onto this are not very good at explaining themselves to people who don't care.