Why is the URL of my links different from what I have chosen?

The URL is different from the one you have chosen because SendinBlue tracks the clicks of your contacts. Through this, you have access to the number of clicks per link, a list of contacts who clicked on each link, and the heat map. This does not affect link's target, contacts are still forwarded to the pages you have selected. It is possible to stop the link tracking and thus your link won't be different.