Does nobody know how to solder any more?
Four things I was taught when learning to solder 50 years ago:
Clean the soldering iron tip with a copper wire brush and tin it freshly before starting.
Scrape the wire end bright with a knife and tin it.
Tin the thing it is to be connected to if it isn't pre-tinned. Those tags look pre-tinned. Scrape them lightly to make them bright.
Use tools such as pliers to make the mechanical joint. Use the solder to make the electrical joint.
OK five things.
5. Do not think of solder as being a kind of 'metal glue'.
You can see in the picture, those tags actually have a little hole for you to poke the tinned wire through, bend into a U shape and squeeze with pliers so it stays there while you bring the solder in one hand and the iron in the other and heat the joint up. Only use extra solder if you need it. You shouldn't. If you have done the preparation properly, the solder will flow quickly and you can whip the iron away after a tiny moment. If you have not prepared, you will cook the whole thing and damage the component and what it is supposed to connect to, and the joint will be bad.
This shows the bending and squeezing although I would have tinned the wire first:
I can't imagine soldering without these: