Whitelist the Reactforce Plugin

Salesforce will digitally sign their official plugins, but external plugins will be presented with a warning message:

? This plugin is not digitally signed and its authenticity cannot be verified. Continue installation? (y/N)

In order to bypass this warning message, the plugin can be whitelisted within your developer environment.

MacOS

Open or create the following file:

$HOME/.config/sfdx/unsignedPluginAllowList.json

The contents of the file should look like this:

[
    "@cloudpremise/reactforce"
]

Windows

Depending on your Windows configuration, add or create the following file:

C:\Users\username.config\sfdx\unsignedPluginAllowList.json

or

%LOCALAPPDATA%\sfdx\unsignedPluginAllowList.json

The contents of the file should look like this:

[
    "@cloudpremise/reactforce"
]

Official Salesforce documentation here.