Every time I turn on my work VPN this password prompt appears
The answer at macOS prompts for password every time I turn on my VPN recommends
You can manually edit which processes have access to the keychain. I don't have a Mac at hand to show you some screenshots, but if you can find out the name of the process demanding the access to the keychain, you can manually always allow it ...
Using a Python 2 script from How to identify which process is running which window in Mac OS X? I've learnt that SecurityAgent seems to be the process that prompts for the password every time I try to turn on my VPN.
Is it dangerous to manually grant SecurityAgent permanent passwordless keychain access?
How can I manually grant it access?