Green’s Dictionary of Slang

throw it v.

[abbr. colloq. throw in the towel]

[1910s+] (Aus.) to stop doing something .

SE in slang uses

In phrases

throw it up to someone (v.) (also into someone’s teeth, up at someone, up in someone’s face)

[late 19C+] (US) to criticize someone, to hold someone up as an object of reproach.