Can't install eWeLink Smart Home 1.2.3

I’m new to Home Assistant, so please go easy on me if I’m missing something obvious.

I saw that some people were having trouble installing 1.2.2 and that 1.2.3 fixed it for them (see Can't install eWeLink add-on - failed to install and eWeLink Smart Home 1.2.2 upgrade failing), but I’m still having the same problem installing 1.2.3. I’m following the instructions on the official Sonoff site. I’ve got the repository installed with no issues. When I enter it and see eWeLink Smart Home 1.2.3, I click “Install” and I get a pop-up which says,
“Failed to install add-on
The command ‘/bin/sh -c npm install --production --save-exact’ returned a non-zero code: 1”

I tried deleting and reinstalling the repository, but that didn’t change the error message. Am I doing something wrong?

There is a much better integration available in HACS: SonoffLan

I would second this. (After initial setup, and if you want to) you could run it non-cloud dependent.