When referencing a resource that you have accessed online there are some additional pieces of information that you need to provide in order to indicate this to the reader. The key additions are:
Author. Title of internet site. [Internet]. year the site was published [cited year month day]; [Number of screens]. Available from: URL
Example:
Macmillan Cancer Support. Rare cancers. [Internet]. 2019 [cited 2022 Dec 15]; [15 screens] Available from: https://www.macmillan.org.uk/cancer-information-and-support/rare-cancers.