There may or may not be a minimum requirement for IF training in the PPL but I defy anyone to teach it to any meaningful level in less than one hour. Ten minutes of the hour is usually soaked up by taxying, power and pre-take off checks, then another (say) ten minutes for take off, climb and re-join leaves precious little time to develop the correct s & l and turning scan techniques.
IMHO we should have kept the minimum 4 hours that we had back in the day. It certainly saved my life, on my first flight after licence issue in 1982, while 4 Belgians died in the same snow storm that was missing from all forecasts. Their licence had absolutely no IF requirement at the time.