Tubes are pretty stretchy. You can use a 700x28-32 in a 27x1-1/4
There’s only a little bit of difference in diameter between 700c and 27” (622mm vs 630). As long as the width is in the same range it’ll work fine. (1-1/4” is equivalent to 32mm)
my 27” bike runs presta valves for convenience (so I can share pumps/tubes with the 700c bikes)