“the government may impose reasonable restrictions on the time, place, or manner of protected speech, provided the restrictions ‘are justified without reference to the content of the regulated speech, that they are narrowly tailored to serve a significant governmental interest, and that they leave open ample alternative channels for communication of the information.’”

People complain about this all the time (“free speech zones”) but it’s been the law for decades.

See also https://www.aclu.org/know-your-rights/protesters-rights .