Once you’ve downloaded the plugin, go to your downloads folder and double click the ‘SquiggleSignatures’ .dmg file to open it.
Step 1: Drag the Squiggle Icon to the Applications Icon
Then go to your Applications folder and double click Squiggle Signatures to open the installer. You’ll then be prompted to start installation.
Step 2: System Preferences
Squiggle needs some system permissions to work. Click the link in the installer window to open system preferences. Then, the padlock in the lower left of the window that opens; you’ll be prompted for your MacOS login password.
Then, drag the Squiggle icon from the installer window into System Preferences, like so:
Step 3: Enable the plugin
The final step is to enable the plugin in Apple Mail. Open Mail, then go Mail ⮕ preferences and manage plugins at the bottom:
On restart, Apple Mail should prompt you to log in with your Squiggle Signature.