@lewlepton@mastodon.social you have to set it up on your phone first. Then you can do it on desktop. One drawback is that signal app is written in electron (ikr), but so is WhatsApp and messenger and actually signal is pretty fast.
Honestly my grandma could set it up with almost no help, but I have to say she is tech savvy for her age (she does embroidery and use her Mac to make design and has a machine to sew) . She still have trouble sharing content from Facebook to signal because Facebook have their own share menu cause you know they want to lock you in, she doesn’t know yet you have to click on the share menu in the Facebook share menu to access the normal share menu to share to signal.