This is not what Popper said. Please read a book.
Popper was as a philosophical liberal. He did not say that intolerant people or intolerant speech must always and everywhere be suppressed, nor did he say that it was always a permissible option to suppress it. On the contrary, he hoped that a free society would permit intolerant speech but such speech would have little effect. Like many liberals, he hoped liberal ideologies would defeat illiberal ideologies in open intellectual combat. He also hoped that liberal political institutions would limit the power of intolerant parties. Constitutional checks and balances could prevent illiberal parties from winning too much power, doing too much damage with whatever power they win, or holding onto power long. Instead, Popper nevertheless asserted that states have a right to censor and suppress illiberal and intolerant political movements as a matter of last resort. In his view, when illiberal parties are actually gaining power, a liberal society may, if necessary, suppress illiberal ideas.
I'm not a fan of Popper but if you're going to cite him as an authority, you might as well get it right.