Improvements

main.py

 #!/usr/bin/env python3
 
-import pyotp
+import argparse
+
 import keyring
+import pyotp
+
+
+def delete_token():
+    if keyring.get_password("unihd", "2fa") is None:
+        return
+    keyring.delete_password("unihd", "2fa")
+
 
 def enroll_token(token_uri: str) -> None:
     keyring.set_password("unihd", "2fa", token_uri)
 
+
+def enroll_token_interactive():
+    mfa_uri = None
+
+    print("Enrolling secret.")
+    while mfa_uri is None or not mfa_uri:
+        mfa_uri = input("Enter/Paste MFA URI: ")
+        if mfa_uri.startswith("otpauth://"):
+            enroll_token(mfa_uri)
+        else:
+            print("The given string has to start with otpauth://")
+
+
 def get_otp() -> str:
     mfa_uri = keyring.get_password("unihd", "2fa")
-    otp = pyotp.parse_uri(mfa_uri)
-    return otp.now()
+    if mfa_uri is None:
+        print("No token enrolled, run again with -e or --enroll")
+        exit(1)
+    else:
+        otp = pyotp.parse_uri(mfa_uri)
+        return otp.now()
+
 
 if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "-d",
+        "--delete",
+        help="Delete the stored otpsecret from keyring",
+        default=False,
+        action="store_true",
+    )
+    parser.add_argument(
+        "-e",
+        "--enroll",
+        help="Enrolls a given token to the keyring",
+        default=None,
+        const="--",
+        nargs="?",
+    )
+    args = parser.parse_args()
+    if args.delete:
+        delete_token()
+        exit()
+    if args.enroll:
+        if args.enroll == "--":
+            enroll_token_interactive()
+        elif args.enroll.startswith("otpauth://"):
+            enroll_token(args.enroll)
+        else:
+            print("The given string has to start with otpauth://")
+            exit(1)
     print(get_otp())