Hello NickiO CS and thank you for your quick answer.
FROM Terms of use / NGC:
"Your Rights to Use the Website Content
You may view, copy, print out, and use content gathered from the Website solely for your personal use, provided that (1) the content available from the Website is used for informational and non-commercial purposes only; (2) no text, graphics, or other content available from the Website is modified in any way; and (3) no graphics available on the Website are used, copied, or distributed separate from accompanying text. Nothing contained herein shall be construed as conferring by implication or otherwise any license or grant of right to use any patent, copyright, trademark, service mark or other intellectual property of CCG except as expressly provided herein."
FROM Numista web site: https://en.numista.com/info.php
"At Numista, we try to have a positive impact on our ecosystem, in various manners:
Ecology: Numista runs on servers powered with hydroelectricity to reduce the CO2 footprint. Also, Numista contributes 5% of premium subscription revenues to fund carbon removal.
Privacy: Numista collects only personal data needed for your usage and comfort on the website. No personal data are shared with third parties, including no third-party analytics cookies and no advertising cookies.
Education: The numismatic catalogue of Numista will always remain free of use for all.
Accessibility: Numista tries to implement all website accessibility best practices. Feel free to report any accessibility issue on Numista. "
It appears that if credit & copyright information were given, a photo from NGC might be able to be used on Numista from this information. But not being an attorney, I still am not sure if it is allowed. Also, I cannot find on the Terms of Use page how to properly give credit if it is allowed