Keep the whole code and its quiet border in the screenshot, then use an image-capable QR scanner to decode it. A tiny, blurred, or heavily compressed crop may not scan; try a clearer source rather than sharpening it aggressively.
Read the decoded text first. If it is a URL, inspect the full hostname and be wary of shortened links or lookalike domains. If the code asks for a login or payment, navigate to the organization's site independently before proceeding.
A QR code hides text from casual view; it does not make that text safe.
Akousa