Install Quantify in Chrome in 2 minutes

Quantify is installed from the downloaded folder, not from the Chrome Web Store.

Steps

Download Quantify.zip and unzip it, for example into your Documents folder. Keep the folder there, Chrome loads the extension from it every time it starts.
Open Chrome and go to chrome://extensions.
Turn on Developer mode (top right), then click Load unpacked and select the unzipped folder that contains manifest.json.
Pin Quantify with the puzzle icon next to the address bar. Click it, paste your key (QTFY-XXXXX-XXXXX-XXXXX-XXXXX) and click Activate. No key yet? See pricing.
Open axiom.trade, log in as usual and trade with Axiom's own buttons. A green P on the icon means you are on paper.

Updating

Download the new ZIP, replace the folder's contents with the new files (same location, overwrite everything), then click the reload icon on the Quantify card in chrome://extensions. Your paper trades and settings are kept. Removing the extension deletes all paper data, so export a backup first (Quantify window, Wallet, Backup).

Safest setup

Paper trade on a separate Axiom account with 0 SOL, for example in its own Chrome profile. Even if Axiom adds a new way to trade that Quantify doesn't know yet, there is no real money to spend. More in the FAQ and on the Features page.