How to get it?

You may get it from official Flipper Zero App Store here. Or, you may build it. Or you may pull the right artifact from latest release and extract it to the root of SD-card on your Flipper Zero. Nightly builds are also available and getting built every day based of the latest firmwares version. After that, you should be able to run it on your Flipper.

To pick the right artifact you would need to know what firmware your Flipper Zero device is running. All the artifacts are named using the same pattern - totp_{firmware}_{channel}_fw_{modifications}.zip, where

Placeholder	Description	Possible values
{firmware}	Firmware name	momentum, unleashed, official
{channel}	Firmware update channel	dev, stable
{modifications}	Modifications of the base application	(empty) - base application without modifications no-badbt - base application without BadBT automation, all the Bluetooth-related code is excluded old-crypto-support - base application with old encryption-algorithms support enabled (useful if you have old config file that you would like to migrate)

Tip

If you are not so sure which firmware your Flipper is running try totp_official-stable_fw.zip first and then if it doesn't work for you then try totp_official-dev_fw.zip.