You can steam foods just elevated inside a lidded pot or pan, with simmering water in the bottom. In other words, make your own steamer.
So for example you could put an inch or so of water in pot or pan or wok, etc, then add some "elevating things" like balls or logs of aluminum foil or even another plate or bowl--possibly upturned. Then put your plate of dumplings on top of the balls/etc so water won't get to the dumplings. Then start heating the water till it's simmering and put a lid on top of the pot/pan/wok so the whole thing becomes a steamer. Steam till done, then remove the plate carefully since it will be quite hot or only the dumplings.
You can use any combination of lidded pot, pan, wok, etc, you have that will fit the dumplings plus whichever kind of elevating thingies and plate/etc you decide to use. You don't want the dumplings to touch the lid though, so make sure there's at least a tiny bit of head room. And you also need at least a little room around the rim of the plate-with-dumplings so the steam can rise from the simmering water and get into the top area where the dumplings are, but it doesn't have to be much.
Dumplings are *very* sticky though so you might want to put a sheet of parchment paper under them, or rub a little oil on the plate, so they will come off more easily, or the plate may be slick enough alone to release them.