Step 1. Generate OTP code from Google OTP application ("Export accounts")
Step 2. Read the QR code(s) with tools (e.g., online qr reader, some python scripts, ...)
Step 3. Extract secret codes from QR code(s) with the script from https://github.com/scito/extract_otp_secrets
Step 4. Install the Alfred workflow: https://github.com/moul/alfred-workflow-gauth
Step 5. Write ~/.gauth
file with the information got from Step 3