Thanks for all the replies.

I am keeping the plant outside in a pot sitting in a recycling crate, in
the sunniest sheltered spot, keeping moist, Covered with plastic at night,
uncovered during the day.

Looks like it is going to lose some or all leaves.

I note that on the James Cook Uni website Capsicum frutescens can be a weed
in north QLD so I suppose that indicates its preferred climate is
substantially warmer than Melb.