How can I change the viewing link and the unsubscribe link?

You can change the text and also the locations of these sentences in your message by inserting the “$WebVersion$” and the “$UnsubscriptionLink$” variables in one of the links of your message.
Thus, you can change the text according to your needs.
If these links are not detected, the system automatically adds the viewing link and the unsubscribe link by default.
 

EXPLANATION:

Edit your message and then :
- Write your customized sentence : “Consult the newsletter with our images”.
- Select “Our images” then add a link.
- In Protocol, select <other>.
- In URL, write “$WebVersion$” and then click OK.
Do the same thing with the unsubscribe link by inserting “$UnsubscriptionLink$” in the URL.