If the surfaces aren't worn down, there is a spray for brake surfaces but I don't recommend this.
Usually a bit of copper-grease on the back of the pads and along the moving edges sorts it out, if there are anti-squeel shims or springs, grease them likewise, very thin amount.
Make sure you don't get any grease on braking surfaces or in places likely to leech to them. Don't use a normal grease, its not high enough temperature rated.
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