I use my windowsill propagator on an extension lead because there isn't a socket close enough. I often have it on a plug-in timer as well, so it only comes on from evening to morning when the ambient temp. is lower (it doesn't have a controllable thermostat and can get too hot in the daytime).
Posts
https://www.london-fire.gov.uk/safety/the-home/electrical-items/cables-fuses-and-leads/#:~:text=Using extension leads safely&text=Always use a fused 'inline,kettles, tumble dryers or heaters.
I'm sure there are forum members who can confirm
They draw a tiny amount of current.
Wisdom is not putting it in a fruit salad.