Australia, Ireland, and UK standard spelling of instill.
her only real object in this call had been to instil a general uneasiness into Diva’s mind about the coal strike 1922, Edward Frederic Benson, Miss Mapp, page 70:
"If we do not instil public confidence in the system, I fear the public will lose confidence and even fewer people will travel by rail." 2020 October 21, “Network News: Labour reiterates demand for full public ownership”, in Rail, page 7: