Accidentally denied access to keychain for a program I need (Mac, obviously) So I have been doing IT support for a long time, for Windows and dabbled in Linux, and while I've had to do the odd thing with Mac, it's usually pretty basic and now I'm stuck. I've got my wife's older mac (10.13) here for testing purposes for an Electron app developed by the company I work for. I updated the program, and then it prompted for the computer password for access to the keychain (because it saves the UN and PW there), which was input and it was ok until I had to restart the app.  When I relaunched it, it prompted again and I accidentally hit Deny. Now when I try to log back into the app, it just spins and spins, no prompt, no error, nothing.
I have completely uninstalled and reinstalled the app naively thinking that might help. I deleted the entry in the keychain, but it doesn't prompt again. I tried adding it back to the keychain manually knowing it wouldn't help, and it didn't. The things I can find online mostly explain how to reset your keychain, but that absolutely cannot be right, because I denied one app, can it?  That seems like a very scorched earth approach.
TIA
I had already deleted the entry thinking that would reset it.  I tried manually adding it back in with the same name.  I'll try it when I get the chance, but that's not going to be the same is it?