Mary, some of these names are made in graphics programs which crafters and designers have on their systems and others are made in online programs, some of which have, 'free to use' areas which have some limitations.
I think, if you googled, free online signatures, you might be presented with some options to try.
I have a graphics program and used to make these some years ago but darned if I can remember exactly how to do them now, lol.

I might have a play around when I get some time ... something I've been very short of lately, lol.
I'm willing to bet there will be someone along to give you some guidance very shortly.
Good luck and I hope you are able to sort something to your satisfaction.