How to proceed on "Login: Checkpoint required"?

Hello, first time trying instaloader 4.15.3. I use args.txt to only pass on my login credentials. I tried instaloader +args.txt myaccount to save my own profile. But I can't seem to get instaloader to login. This is my terminal output:

Session file does not exist yet - Logging in.
Login: Checkpoint required. Point your browser to /auth_platform/?apc=[redacted] - follow the instructions, then retry.

The above generated URL points to nowhere. Prepending https://www.instagram.com doesn't work, either. I don't understand nor see any pointers in the manual how to proceed here.

Thanks! BF